Planting, Growing, and Caring for Delphinium
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Oh, the delightful delphinium! The stalwart of many summer flower gardens, these showy perennials are grown for their long, colorful spikes in blue and other gorgeous hues. Flowering all summer, delphiniums are butterfly and hummingbird magnets, too! Learn how to plant, grow, and care for delphiniums.
About Delphinium Flowers
Delphinium is a genus in the Ranunculaceae family. (They’re often confused with larkspur, which are a different plant species.) There are more than 300 delphinium species, so there is quite a variety of heights, from dwarf hybrids to 6-foot tall beauties, so they can be planted in the front, middle, or back of a perennial border. The blue delphinium is most common, but varieties also come in gorgeous shades of violet, pink, white, red, and purple. They are popular in both cottage-style and cutting gardens.
Most delphiniums are short-lived perennials, lasting 2 or 3 years in the garden. Some varieties will bloom throughout the entire summer if the plants are cut back regularly. Other hybrids bloom from early to mid-summer and will produce a second flower display in late summer or early fall if you cut off the old flower stalk.
What’s important to know about delphiniums is that they will thrive if you meet their specific conditions. Delphiniums prefer moist, cool summers; they do not fare well in hot, dry weather or sudden wind or rain, which can knock them down. Most varieties will need staking. See more details below.
Are Delphinium Poisonous?
Yes, delphiniums are highly poisonous. If seeds and seedlings are ingested, they can cause nausea, twitching muscles, paralysis, and even death. This is mainly a concern for grazing animals such as cattle, horses, and sheep, and it is also a caution to gardeners with small children.
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Planting
Choose a spot in full sun with shelter from strong winds. Stake early in the growing season; delphiniums’ heavy flower spikes grow on hollow stems, which can easily break. Soil should be fertile, well-draining, and neutral to slightly alkaline (pH of 6.0 to 7.5). Prior to planting, loosen the garden soil and mix in 2 to 4 inches of compost or aged manure. Do a soil test and, if needed, add lime, wood ashes, or a mixture of the two to this alkaline-loving perennial.
When to Plant Delphinium
- Plant delphinium in the spring as a transplant (small plant started by garden nursery)
- To start indoors, sow seeds about 10 weeks before the last spring frost.
How to Plant Delphinium
- Dig a hole twice the diameter of the plant’s container.
- Make sure that the top of the root ball is level with the surface soil.
- Fill in with soil.
- Water thoroughly
Growing
- Delphiniums are heavy feeders. Apply a balanced liquid fertilizer starting in early spring every 2 to 3 weeks.
- Insert sturdy stake supports no later than mid-spring or when the plants reach 12 inches high.
- Do not allow the soil to dry out, but avoid puddling. Water plants during the summer if rainfall is less than 1 inch per week.
- For ideal flower spikes, thin side shoots at 3 inches high, leaving 2 or 3 shoots on young plants and 5 to 7 shoots on mature, well-established ones.
- Deadhead by cutting spent flower spikes back to small, flowering side shoots.
- After delphiniums have finished blooming, cut flower stalks to the ground, and new, though smaller, flower stalks will develop. The flowers will survive the coming cold days and even light frosts. (See local frost dates.)
- Every 3 to 4 years, divide plants in spring: Remove and replant the new little plants growing around the outside of the clump. Discard the hard old heart.
Types
- Belladonna Group: blue flowers native to North America; easier to grow and longer-lived than varieties in the Elatum Group (below); upright, loose, and branching perennials; secondary flower spikes extend bloom period into autumn; 3 to 4 feet tall. ‘Blue Donna’ has clear, blue flowers.
- Elatum Group: tallest varieties in shades of violet, blue, pink, and/or white; short-lived; reach 6 feet tall or more. ‘Aurora Deep Purple’ has purple flowers with a white center.
- Pacific Hybrids: 3-inch violet, blue, and pink flowers; short-lived; tolerate warm/hot climates as annuals; giant (3- to 6-foot) heirlooms and dwarf hybrids. ‘King Arthur’, 5 to 6 feet tall, has plum flowers with white centers.
Harvesting
This elegant flower is good for a cutting garden. Cut flowers for arrangements when at least one bud is showing color and one bud is starting to open. Vase life is 6 to 8 days.
Gardening Products
Pests/Diseases
Diseases: aster yellows, blight, leaf spot, downy mildew, powdery mildew, mold, crown and root rot, gray mold, rust, viruses, smut, and wilts.
Pests: cyclemen mites, nematodes, slugs and snails
Wit and Wisdom
- The name “delphinium” is derived from the Greek word delphis, meaning “dolphin,” as the closed flower buds were said to resemble a dolphin’s nose.
- The centers of delphinium flowers are called “bees.”
- Don’t get discouraged if you try to grow delphinium from seed. Use fresh seeds; put them in egg cartons in the fridge using damp seed mix; after most have sprouted, put them under a bright light. Normal to cool room temp.
Catherine Boeckmann
Executive Digital Editor and Master Gardener
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Comments
Hi, Vickie. For heat zones above zone 7, it is recommended that you grow them where they get afternoon shade. Consider them to be short-lived perennials in your zone or you can grow them as annuals.
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Will the seeds winter over outside, or do I have to keep inside and germinate in the spring to later plant outside?
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Hi Patricia,
Delphinium seeds need a cold period for spring germination. The recommended approach is to harvest your seeds once the flowers have all faded. At that point, cut down the stalks to the ground and hang the stalks indoors to dry. Once the seed pods begin to split (after a few weeks), remove the small seeds and store them in an airtight container in the refrigerator during the winter months. About 10 weeks before your last frost date, remove the seeds and begin the germination process indoors. Plant the seeds in evenly moist soil (just not too wet) covering the seeds with about 1/8 inch of soil. Seedlings should emerge in 21 to 28 days. Once seedlings appear, provide plenty of light. Before planting outdoors, harden off your seedlings.
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Thank you for this wealth of information. How many seeds do I need to pland in one place if I am starting them in a pot or the ground?
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My delphinium is huge and extremely sturdy. The flowers are starting to fall away and I noticed what appears to be green seed pods. Can I collect these and sow them for more plants? I only have the one and it comes back every year, but no others have developed around it.
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Once your delphinium flowers have all bloomed and gone away, it is time to cut the plant's stalks to the ground. Hang the stalks, which include the green seed pods, in a spot to dry. After a few weeks, you will notice that the pods begin to brown and split. You can also hear the seeds moving around inside the pods if you give the stalk a shake. Break open the pods to remove the tiny seeds and then store them in an air-tight container or zippered plastic bag in your refrigerator over the winter. Delphinium seeds need a cold period over the winter for spring germination. You can start the seeds indoors 8 to 10 weeks before the last frost.
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If you germinate seeds indoors & they germinate, when you transplant them outdoors, can you expect to see blooms THAT year?
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Yes, if you germinate delphinium seeds indoors and transplant them outside, you can generally expect blooms that same year.
But keep in mind that this assumes you're planting them early enough to mature before the fall frost. Check your seed packet.
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When you say young ones are poisonous, do you mean 'early in the Spring' young or a plant that is one or two years old, rather than a mature plant of 20+ years? Thank you.
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The new leaf growth of delphiniums tends to be the most poisonous exposed part of the plant, so delphinium plants are more toxic earlier in the year than they are later in the year.
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Are they poisonous if chewed by a dog ?
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Yes.. (poisonous means poisonous) ... kinda like drinking gasoline. If humans can't drink it. Then any other living thing probably shouldn't drink gas.. .... next question I'm assuming Are fires hot? Since fire burns me, will it burn my cat? Hahaha People people people...
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....humans can eat onions but dogs cant. why do you have to act like this is such a dumb question? you dont look smart, you look rude.
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Well said. Snarky answers show not only the poor character of the sender, but often his or her ignoranceas well. I love onions and chocolate. I won't give either to my dog. I love cinnamon and mint essential oils, but I won't diffuse them near my rabbits. Not every creature is the same. Kindness always makes one seem wise. Rudeness tends to reveal the opposite.
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The sarcasm is not necessary and adds nothing to the content of the question or response. Just shows bad character.
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The sarcasm is not necessary and adds nothing to the content of the question or response. Just shows bad character.
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Delphiniums are starting to grow nicely, however, noticing a shiny look to some of the leaves. Is that a sign of some disease.
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A shiny residue on leaves could indicate that slugs or aphids are present. Check out our https://www.almanac.com/gardening/pests-and-diseases">pest pages for information about dealing with them!
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Thank you for your very helpful information regarding delphiniums
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I live in Massachusetts. I bought some seeds this winter and am now nervous about planting them. Are Delphinium harmful to the local wildlife? Birds, pollinators, squirrels, bunnies, etc?
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Delphinium are only harmful if ingested, so rabbits and deer would be most likely to be affected. Generally, these animals will only take a nibble of the plant (not enough to harm the animal) and then be turned off by the unpleasant taste. If these grazers visit your garden regularly, consider covering the delphinium while they're young (and most toxic) or planting them in a container that can be placed out of reach.
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No they aren’t only harmful if digested you can’t touch them they can cause skin irritation all parts of Delphiums are poisonous
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to: Submitted by Ann Legere on June 16, 2020 - 12:39pm I am not sure about Lupins, but I can say I had a deer come through my flower bed. Ate all the tops out of my fuschias, roses(of course), crocosmias, violets, but didn't touch my delphiniums which were only a couple feet away.
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Can you me if deer are attracted or will eat Lupins or Delphiniums? Thank you for any info you can give me. Ann Legere
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Both plant are considered deer-resistant and good choices in gardens without fencing. (Just keep in mind: NO plant is truly deer-resistant if deer are hungry enough; however, some plants are more resistant than others.)
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my delphs are well up. should I cover them for -9 degrees c.prediction?
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No worries. Delphiniums are a hardy herbaceous perennial, which means they are fully hardy down -10 to -15C and between 5 - 14F. In late autumn and winter they die back completely to bare earth and regrow each spring. Note: They do need shelter from winds and best planted in a sheltered spot away from winds. They have heavy flower heads supported by hollow stems. Also, all delphiniums need staking as soon as they have put on growth and are getting established.
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How big should Delphiniums be before transplanting them from under the grow light to outdoors?
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Kudos for getting sprouts, Jack. Height is a consideration but you want seedlings with "true" leaves, not just the two that initially appear. True leaves appear early, so if your plants have a couple to a few inches, you're probably well past that stage. As for height, we've see suggestions of 12 to 15 inches but it depends on the strength of the plants. Before transplanting you also want to harden off the plants—get them used to the world. Here is some advice on that https://www.almanac.com/video/how-harden-plants and another https://www.almanac.com/news/gardening-news/time-get-toug... (these are about vegetables but the process is the same).
We hope this helps!
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I want to grow delphiniums indoors in a south-facing window with small period of shade from trees throughout the day . A/C will be maintained to 80 degrees or less Any chance of success?
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Hello, my wife and I really like delphiniums but we hear that they are very difficult to grow here in the coastal southeast, zone 8b. Nevertheless I purchased some and planted in good, composted soil. What tips can you give me that would heighten my chances of success? Also are there any varieties that would do better than others in this area. I realize that they would be only annuals. Thank you.
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I live on the southeast coast of Florida, can I grow these in the ground in partial shade?
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Delphinium is technically a perennial, but it can be grown as a winter annual in Florida. Otherwise, Florida is just too hot and wet for this cool-weather plant to survive a summer season.
Delphiniums do need full Sun to grow but they prefer cool weather. So let seeds germinate in winter and the plant will bloom in early spring. Once temperatures rise in summer, the plants will fade and you'll need to remove them.
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I have 3 delphiniums (pale blue/white) growing and flowering nicely in a pot on the deck in SW Iowa. How should I winter them to see them grow and bloom in the Spring again?
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As noted at the top of this page, delphiniums can be a challenge; not all grow as perennials. Many are short-lived plants. Knowing that, you could experiement: Cut them back as advised in Care above. Put them into a garage or basement and water them occasionally. Or, if you are in zone 7 or lower, lift them from the pot now and plant them (you could also plant the pot), then lift them in the spring and repot to see if they come back.
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There are two conflicting suggestions on this page regarding the ideal soil pH for growing delphiniums. The intro says they are alkaline-loving, but later you say that the soil pH should be between 5.8 and 6.5. A pH of anything less than 7 is considered acidic, not alkaline (basic). Please clarify what the ideal soil pH should be for successfully growing delphiniums. Thank you!
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Thanks for catching that! The information in the intro is correct: Delphiniums prefer alkaline soil, not acidic. Your soil should stay on the lower end of alkaline (between 7 and 9 pH), however.
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After many years of growing Delphiniums, I finally figured out how to protect them during our often snowy winters in New York. And I 'm gardening in very large pots on a terrace. I don't have to lift them or bring them inside. I just put sand around (not on) the plants so that even as the snow melts, even if it's a rainy winter, they have good drainage. You can get the sand at most hardware stores. I now lose very few delphiniums I currently have 5 that are two years old and 3 that are 3-years old. They don't last forever, but if you their roots have lots of room to grow, they can become very tall--even over 2 years. Some are now six feet tall, and even in containers, they have spread to 2-3 tall delphiniums that bloom twice each summer.
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I live in Minnesota. Last year I planted some potted Emperor Delphiniums (dark deep purple with white bee) And one or two light blues, they grew about 2ft. With at least 2 stalks. After fall was well over and just before winter began I cut all of them back. It’s finaly spring here no more snow all the snow I think has finaly melted and we have had 4 days of over 58* degrees in a row w/ no weather below 60 in the forecast.. other spring flowers are growing out of ground. Dafadiles etc. when will my DELPHINIUMS start to show some effort of growing my garden is bare.
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Bought this plant in full bloom 2 years ago and planted it in a new bed with fresh deep earth and mulch. It has half a day in full sun and half a day in shade. It grows nice strong thick 5 to 7 leafy stalks growing tall to about a yard and a half tall, and puts all its growing to growing green and tall throughout the spring and summer but for the last two years , no flowers at all. How can I get this plant to produce flowers?
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I don't know what the dead part looks like. Sometimes I think the white is dead, but other white looks like it's the new blooms starting. What is the green pod? Should I remove it. The only thing I am confident about is when the blue dries out! Could you post pictures of the parts and what to deadhead?
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Sounds like to me, you did not get any pollinators (Bee’s or butterfly’s) that first year they were planted. Awe that’s sad. It’s best to plants several pollinator favorites together at the same time. To guarantee they smell and will come. Marigolds, purple hyssops, Phlox and candy tuff, they like keep in mind flowers are Regional and species by favorite. Meaning each region has specific butterfly’s and therefore each species has their favorite flowers. Check for the species that favor your region and plant their specific favorite flower .. I don’t know if it is too late for your flowers to bud.
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Hi I bought some beautiful delphinium plants mid July. The nursery had them in the Perennial section. I hooked the informations to each plant but either birds ran off with them or ? Anyway...they all went to seed and I took all the little pods off and emptied the seeds into baggies. Now Im wondering if that was right? Should I go dump the seeds with the plant? Im not a good gardener...Ive been told non jokingly that I should not have a yard! I agree. So what do I do with the seeds? Deb
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You could dump the seeds near the plant. Some delphs grow easily from seed, some do not. If you want to grow the seeds (or plants) sucessfully, you should test your soil. Here's some advice: https://www.almanac.com/news/gardening/gardening-advice/h...">https://www.almanac.com/news/gardening/gardening-advice/h...
Delphiniums do poorly in acidic or neutral soil. So, if you prefer not to test at this time, broadcast lime, wood ashes, or a mixture of the two over the soil you would use for this alkaline-loving perennial. https://www.almanac.com/news/gardening/gardening-advice/o...">Learn more about soil amendments.
Overall, re whether the seeds will set, consider contacting the source you bought them from for information. They may be able to tell you what type they are.
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I have just purchased 2plants in pots is it ok to plant out now
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I have seen delphiniums on sale now. Can I plant out now?
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Hi Mary,
It's too late to plant delphiniums now; they should be planted in the spring. Delphiniums don't like hot, dry weather like that of the summer.
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I know it's not ideal, but I have a delphinium in a shady garden that needs to be moved. The whole bed needs to be dug out and redone. My question is, will it be worth the effort, or will I kill it? It's a nice big plant, and I do have a better location for it. It is blooming, but the stems all fell over, and are laying flat. So I thought I would just cut them off totally, then move it. I am in zone 3b, and we are having 80degree days, 60 degree nights.
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There may be several factors that put the plant at risk, not moving it alone. Soil conditions are key: well draining and alkaline being paramount, and a thin layer of compost each pring, followed by 2 inches of mulch to help retain moisture (soil should not dry out) and deter weeds. Lifting and dividing should be done in the spring; can you wait?? These plants are not fond of heat. So that and lack of sun (they'll tolerate light shade) could be the reason/s its flagging. Remember, if you lose it, you can get another one.
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I have just resented planted my first delphinium and it has been growing great. The top has blooms on it but has not bloomed yet. We had two days of downpours getting maybe 5inches in two days. Now the top of my flower has dropped over. What do I need to do? Will it snap out of it?
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If the soil is soggy, the blooms will drop. Let the soil dry out and the plant should recover. Also, it helps to stake delphiniums to prevent damage in a rainstorm. Use some natural twine around the plants, just below the flower heads, without actually tying them up.
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Can I plant in a large pot? Is it an annual?
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Delphiniums are perennials, so they will come back each year as long as they are hardy in your http://www.almanac.com/content/plant-hardiness-zones">planting zone. You can plant delphiniums in pots, but be sure to use a pot that has a drainage hole and has loose, well-draining soil.
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Hello! We recently had some heavy winds and I was unaware to stake my delphiniums in the spring so they all tipped over. I tried lifting a couple but two broke at the base so I stopped moving them. Can a person still salvage them somehow? Will broken ones still come back next year? Thanks!!
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Good question! If your delphiniums were allowed to bloom normally, you would cut back the stalks after the flowers died. Your delphiniums should have no problem coming back next year.
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I recently purchased and planted my Larkspur in a large pot on my patio The flowers are blooming, but the leaves appear to be burning. It gets morning and mid day sun. Any suggestions?
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If by burning you mean turning yellow, your plant could be afflicted with a disease and, honestly, there are too many options to cite here. At this link << http://extension.psu.edu/pests/plant-diseases/all-fact-sh... >> you will find a number of conditions, symptom descriptions, causes, and remedies. We hope you can find a solution...without having to destroy the plant. However, if that appears to be the best "management" as it's called on this chart (at the link), you should consider returning the plant to the vendor, as the disease may have originated there, or at least telling the vendor of your experience.
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I bought one and it is dying I keep it watered what am I doing wrong
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I bought one and it is dying I keep it watered what am I doing wrong
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I cut my first set of very tall and bountiful blooms down and the shoots that are coming up now are already set to flower. However the spikes are significantly shorter and have many less buds. Are they usually supposed to have this happen?
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It is typical of delphinium's second bloom stalk to be smaller than the first. Take heart in the fact that you are doing everything right: Some gardeners find this a difficult plant to grow!
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I live southeast Houston and I purchased my delphinium about a month ago. I had to cut down one spike that had already flowered a week after while another was shooting up. I also managed to get rid of its cyclamen mite infection by giving it a hot water bath for 30 minutes. My question is regarding the new growth that is yellow with green veins and a lot of is drooping. The other spike is now flourishing but shows no sign of distress. I have given the plant plenty of compost and regularly bury 3 banana peels in the soil every week. Could it be that I didn't water it enough? Could it have anything to do with the very small amount of diluted urea I gave the plant two days ago? Am I applying too much neem oil? Also, what is 1 inch of rain per week in gallons?
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All in all, the plant has been through a lot during its month in your care: A stalk was amputated. It was soaked in hot water. Why the bananas? These are traditionally said to benefit to roses (and some dispute this). Diluted urea? Why? Neem oil? Why—does it have looper worms? (Search "neem" on this page for more on this.) Has the plant had time to get acquainted with its new home? Does it get sun? It sound like you've watered it plenty. Is the soil damp? If so, it's watered. One-inch of rain per week is watering until the water soaks down 1 inch. You should just water when it is dry. Delphiniums do not like "wet feet." We suggest that you read the care tips above and the reader comments and our responses below.
About the new growth that is yellow with green veins and is drooping: this may be a sign of an iron or magnesium deficiency and/or it could be a sign of improper pH. Do a soil test; you want a pH that is at least slightly alkaline.
You should also consult your local cooperative extension. Click here http://www.almanac.com/search/site/cooperative%20extension chose your state, and find the service nearest you. The folks here are very helpful!
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After the other stalk had been spent, I decided to cut it to make another shoot sprout later in the year. I gave it banana peels because I read that they are great organic fertilizers with high potassium and phosphorous amounts that encourage healthy blooms. I gave it diluted Urea for the high nitrogen count and Neem oil to prevent the return of the Cyclamen Mites, powdery mildew, and other diseases. I've also applied an iron/magnesium/zinc solution to the foliage per the label's instructions for faster and safer absorption. It was a very damaged plant when I first bought it so I tried to give it extra care aside from the plants natural high demands. The PH is right around 6.2. I tried to keep the soil moist per all the discussion posts I've read but it gets very hot and windy in Houston and the plant would often dry out so fast that I wouldn't be able to keep up with it. Anyway I kept it in partial shade and watered it each time 1 inch of topsoil dried out. The problem is that I was advised to never let it dry out but constantly keeping it moist might have let to root or crown rot. However I don't see any fungus, there's no pungent smell, and the plant is otherwise flowering through side shoots off the second stalk. I've tried to control its environment but this Delphinium has been a very challenging experiment. I'll apply some more iron application and keep the moisture level even but is there any other preventative measures I can take?
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Our only thought is, as noted above, to contact your local cooperative extension and ask the advice of experts there. Being "on the ground" and familiar with local conditions they may have insights or comments.
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I reached out to TAMU agriculture and they were great. Thank you for all of your insights, I really appreciate it!
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Delphiniums are very difficult to grow from seed. Buy as a potted plant at the nursery- where did you find this info? Delphiniums are so easy to start from seed, just drop them in the fall - presto your will have lost 1/2 your garden to delphs in 3 years!
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do the flowers produce seeds to plant new plants?
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There are many different varieties of delphiniums--some are annuals, others are biennials or perennials. Some grow easily from seed, others don't. Climate also plays a part. So the best thing to do is save some seed and sow it in the spring. Hopefully, you will be rewarded!
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Hello, I started some seed on wet paper towels in black styrofoam to go boxes. I started them on 9/6, once they sprouted about 10-15 days later, I plucked them from the paper towels and planted them into to a 72 cell self watering seed starter tray with a clear cover/hood. They have shot up to about 1" tall with 2 very nice leaves. They are currently in my livingroom window. I live in Beaverton OR, zone 6 or 7. My question is, with this being the begining of fall, do I dare move them out gradually now so to get them ready for winter, and if not, will they survive indoors all winter until spring? Or in other words.....HELP!!
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Dont get discouraged about growing delphiniums from seed. Use fresh seeds. I put my seeds in plastic egg cartons, and put them in the fridge using damp seed mix. I have good success. They sprout in the fridge. After most have sprouted, put them under a bright light. Normal to cool room temp. Start 10 weeks before last frost date.
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I live at 9000' in Colorado and have had huge successes with my delphiniums but this year most of my plants were green and bushy but no blooms, although several did bloom in other parts of my gardens. What is going on??? Thanks!!
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Hi Mary,
It is possible your soil is depleted of necessary nutrients that encourage blooming. If a plant is stressed in any way, it puts more energy into root and leaf production than into flowering. Consider getting your soil tested to determine if this is the case.
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I have 2 purple and 1 pink delphinium. All are wonderful this year, I believe they are pacific Giants. Could you recommend where I might buy a light blue delphinium plant and a white delphinium plant. Thank you.
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Sugar will only speed the decay of delphinium or any other cut flower unless you also add a little bit of bleach and some lemon juice. Use commercial floral food instead. Here is an article about extending the life of cut flowers. https://www.mastergardeners.org/picks/extendlife.html I am a certified floral designer and a Master Gardener. I would never use straight sugar in my arrangements.
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Thank you for this advice—we have updated our page to reflect the information!
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i live in northern southeast alaska and have a whole bunch of delphiniums, they survive very well here and it gets done to 20-30 below 0-F for a short time in the winter. i started out with sandy soil, added horse manure and in late fall, i put about 5" of straw all around the plants.
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i live in Northern Ontario, and just planted 4 new 2 ' tall delpinium plants we had a big day of rain and one was sitting in a puddle of water our earth is nice black mud, but should i uproot the puddle plant and let them dry out a bit in a pot or let nature take its course tks
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Delphiniums don't like "wet feet" and if you have a puddle now it will happen again. The soil needs to drain well so we suggest that you dig up the plants and amend the soil with compost before replanting. Or move the plants to a "drier" location.
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2 years ago I planted 10 delphinium plants. They all came back up last year and bloomed beautifully. This year I have six that did not come up. Any chance they'll return next year, or are they dead? I want to replace them if they won't return. I am in Clarkston, MI - zone 5b
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There are a few varieties that are biennial and bloom every other year. If you planted 10 plants that were the same variety chances are that the six that didn't come up this year are dead. It's helpful to know the name of the delphiniums that you plant. You can then look them up and get details on the variety.
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I bought my first dark blue delphinium in July and it already had four blooms on it. I had cut the flowers off when they lost their perkiness. After the blooms were gone I left the plant in it's original pot. About four weeks later new growth was coming from around the base while the original leaves,very dark green, slowly dried out and I cut them off at the base so more energy would go to the new leaves. I also repotted the plant. The new growth is triple the size of the original and the leaves are not dark green. Now a stalk has come up and the buds are growing. I noticed that in between the top buds are black fibers or very small skinny leaves. Is this normal? Should I pluck out the black fiber things? I live near Milwaukee, Wisconsin in a condo on the second floor. Any idea how to store it over the winter? I do have room in the basement that will go no lower than 42F degrees. Or do I put it in a styrofoam container with lid. And because of my potted situation, what care should I give it during the winter? Any help is welcome!
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Cut the plant down to about 6 to 8 inches after the first killing frost in autumn. You can then store the pot in the basement. Just remember to water the plant a couple of times during the winter months just so that the roots don't get too dry.
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Comments are to plant in spring, can I split and transplant now in August? I live in nw Ontario not sure of the zone.
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Hi, Trucia: Delphiniums are not the hardiest plants to divide and transplant to begin with (starting from seed often works better), but if you do wish to divide and transplant, it's best to do it in the early spring, after they've had a chance to regroup over the winter. Then again, there might not be much to lose, so up to you. Thanks for asking!
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I grew my first ever delphiniums from seeds and have 4 plants that are very tall and planted up against the porch rail that I use to give them support. My question is...I live in zone 8b. Will my dephiniums come back next year or should I consider them as annuals?
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For heat zones above zone 7, it is recommended that you grow them where they get afternoon shade. Consider them to be short-lived perennials in your zone or you can grow them as annuals.
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Hi, I'm in Edmonton Alberta, our Delphs are huge, tall, and full, we're very happy with them, except that once a season the rain or wind will pummel them or the weight of them will bring a bunch down, I didn't realize I could stake them, my question is this, if they're grown is it too late to stake them? The ones that have been knocked down from the wind, should I cut them back and see if they'll get a second bloom, if they do would I stake the second bloom? It's mid July so realistically In Alberta I'll get good weather all of August at least most of sept and some years we won't see first frost til early oct.
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Hi, K-Mi: You can always stake anything at any time. What we mean by the advice above to stake when they are small is that this is the best way to help them get tall. But if yours get tall without any staking to begin with, that advice is irrelevant. So go ahead and stake what you have standing. Cut back what has fallen and then stake what regrows when that happens. Good luck and thanks for asking!
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Our delphinium have never done well. Out of the original three plants, only one survives (@ 4 years). Now that I've read all these ideas, we're going out back with manure, lime, and two new plants! Wish us luck! We live in central Massachusetts.
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I have beautiful, green foilage on my 3ft high delphiniums but never any blooms. When they were new, they bloomed the first few years. Now nothing. I keep thinning them out to no avail. Why won't they bloom?
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How is the soil? Delphs are heavy feeders: they benefit from fertilizer and/or compost in spring and summer, and some say balanced fertilizer every 2 to 3 weeks, in growing season. Soil must also be well draining. They do not like dry, hot climates; sound like home? They like full sun to partial shade. We're betting that this, in whole or in part, is the main issue.
Do you prune/cut off lateral flower spikes? Doing so may help the main spike to bloom.
Do you cut back stalks to basal leaves in fall? This could help but not until next season, of course.
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I have a healthy looking delphinium with about 4 flower spikes but 2 of them only have a single flower at the top of the spike and no other buds down the stem! What's going on? I live in the UK.
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I have one successful Delphinium plant at one end of a raised bed. (I planted it last year and it came back, looks OK and is budded to bloom). I planted several more this month (May) in the rest of the bed (sandy soil with accumulated compost of several years). They are not wilted or looking distressed EXCEPT that: some of the new plants' leaves are yellow, with the green restricted to the veins, although they not curled and I don't see any insect damage. The yellowed leaves have long petioles. I applied generous amounts of compost today (5/31) and watered it in. I doubt the pH of that soil is as much as 7 and wonder whether I should add lime to make it more alkaline?? But if pH is the problem, why is the first Delphinium I planted last year doing all right?
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Yellow leaves with green veins is typically an iron or manganese deficiency, which are not typically found in commercial fertilizers. However, it may be that the pH is off and those micronutrients are in the soil, but not available to the plant. There are simple pH testing kits that you can buy at most gardening stores. Make sure that the pH is between 5.8 and 6.5, which is where most plants like it to be.
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About 2 weeks ago I bought some Delphiniums at the local big box store. I wonder if they have leaf miners? All the older leaves have dead brown edges that curl under. I don't see little lines of eggs on the back, nor actual trails I can follow moving across the face of the leaf. But large areas of the leaves are covered with light tan speckles and thin lines. The area is thickened and very stiff, with a heavy, bumpy texture on the top surface. Can anyone confirm, please?
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I live in North Florida and you can imagine the summers are hot and muggy. I know it's said that growing from seeds is difficult, but I'd like to try. Do you have any tips (if seeds do their thing) for care in this climate? I'm just concerned because: "They prefer moist, cool summers and do not fare well in hot, dry summers." and I'm a mix of the two...the better two I hope. Thank in advance.
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Hi Chellina,
In Florida delphiniums are best planted in mid- to late autumn or very early winter for spring blooms during the cooler months. They will probably not survive your humid hot summers.
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Jacksonville...I got about two months of beautiful blooms. Started in the fall last year.
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I have started these from seed and it is difficult but not impossible. I live in Idaho, started seeds in the early early spring. It would have been better if I had put plastic over the pot after planting seeds as a sort of hot house, you may not need to do this with your humid weather in Florida tho. Many came up but not many survived to transplant size. Good luck!
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I never had any luck until I planted them in a nursery bed in the fall and let them overwinter. I imagine in Florida you'd have to refrigerate the seeds before planting them out.
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Use mycorrhizal fungi when planting and in watering. They are EASY to start and grow this way.
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I purchased a couple of Delphinium plants from Lowes on clearance because they were a little brown. I assumed they were dry and just needed to be watered so I purchased them and mixed in Miricle Grow with the soil. I watered them and kept the soil moist. They did alright for a week but then they all turned brown (stalks and leaves). When I LIGHTLY pulled on the stalks they broke off at ground level. Did the Delphinium's die or will they come back next year?
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There are several reasons for brown foliage on delphiniums. Sometimes it's overwatering. Sometimes it's lack of nutrients; delphiniums are heavy feeders and appreciate compost and fertilizer. Towards the end of their cycle, the foliage simply turns brown as it dies down naturally. They should be back next year.
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Thank you very much. You guys are great and I will keep coming back to you.
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I believe what happened is you put a fertile too high in nitrogen the best fertilizer for transplanting new plants is hastagro organic fertilizer or Bills Perfect Fertilizer because it reduces transplant shock. You need something around and (not exactly ) 5-10-12
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The rain has pummeled my Delphiniums so that they are lying on top of each other on the ground and the stems snap when I try to lift and re-stake them. Mostly they are starting to go to seed. Would it be ok to cut them close to the base so I can clean up this tangled mess or should I do my best to remove only the spikes and leave the rest until the stalks turn Brown, or something else? The flower bed is HUGE and almost completely comprised of tall Delphiniums.
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Hi Juliett,
Just cut the spikes to the ground leaving any remaining foliage. Water and your plants may regrow another flowering spike before the end of the season.
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A couple of years ago I rebuilt our raised flower garden in our back yard using PT wood and everything we planted there (phlox, saliva, foxglove, lilies, etc.) has thrived so when it came time this year to rebuild the raised flower bed in our front yard, I felt confident using PT wood. I made a "concoction" of dirt using Scott's topsoil (they say it contains peat moss, but it can't be much), garden soil, additional peat moss (to keep the ground loose) and I threw in a little milorganite to boot. About a week ago we planted phlox and delphiniums and, after planting, I soaked the bases of the plants with Miracle-Grow's QuickStart (I followed the directions). The next day I soaked the ground with water and the third day another dose of the QuickStart. I've been watering every day since. The phlox are THRIVING!!!! It's only been a week and they all have new stems with buds coming up. The delphiniums, on the other hand, while not appearing to be dying, don't seem very "happy." The leaves are green, but all the edges of the leaves are drooping. Am I just being impatient or am I doing something wrong? Thanks!
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Soory! Forgot to mention that I live in Wisconsin, zone 5.
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We really enjoyed your post and hearing about your gardening experience. Congrats on the phlox success. In terms of the delphiniums, perhaps it's just wilting with the heat. Be sure to deadhead delphs after blooming, too. All the best!
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Not sure it can be from the heat. It's the end of July and we're still waiting for summer! We've had about four days in the low 90s, maybe two weeks total in the 80s, the rest of summer has been 70s (even came close to breaking a record low for last monday). If I understand correctly, once the delphinium flowers die, they should be deadheaded asap? Thanks!
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Delphiniums like moist soil, not soggy and not dry. Try to water deeply a couple of times a week. Adding mulch around the plants will help to keep the soil moist and the roots cool. Deadheading spent flowers will promote new growth and maybe more flowers before the end of summer.
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I have a couple of delphinium plants that have been consistently pathetic looking. They don't grow, never bloom and just take up space. I finally read somewhere that they like an alkaline environment, so I put some lime around each one. Well they are both putting up new sprigs. I wish I knew this earlier.
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It's mid July in Illinois and I planted my delphinium about one month back. It gets full afternoon sun and the summer has been very hot and humid this year. All my flowers have fallen off and the stalks and leaves are turning brown. I water the plant about three times a week and it has a nice layer of mushroom compost on top of the soil. I have not cut anything back yet. What am I doing wrong?
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Since the leaves are turning brown after just a month, in addition to the flowers (which might fade just as part of their life cycle), it might be the heat. If the temperatures have been very hot (around 90F or above), with the full afternoon sun on them, it could stress the plant enough to dry it out. Provide partial shade during the afternoon hours. Another season, if hot temps are frequent in your area, you might try planting your delphiniums where they would get morning, rather than afternoon, sun. You might also try heat-tolerant varieties. Mulch is great, and will help to keep the soil cooler.
Also check your watering. Over- or underwatering can cause browning foliage. Water deeply and provide about 1 inch per week, adjusting for any rain or hot weather you might have; during hot spells, increase to every other day. Don't let the soil dry out, but don't let the soil get soggy either.
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Bugs - many bugs! I started my delphiniums about 6 years ago & they have done amazingly until this year. Their growth was stunted & some of the leaves looked heavy, shiny & sticky. There was a "bazillion bugs under the leaves! The double white never made it through the Winter (zone 3) & the other 3 were so infested I cut them back completely. Husband asked if they were gnats. I have no clue - anybody have an idea?
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We're not sure, Melissa, but here are two coop ext site in which you might find a match with your plants' conditions:
• http://extension.psu.edu/pests/plant-diseases/all-fact-sh...
• http://www.gardening.cornell.edu/homegardening/scene09de....
We hope this helps.
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Hi, My name is Marilene I am in Ireland and I planted my little purple beauty three weeks ago. Delphinium 'Blue Fountains' We are having lots of unusualy long hot sunny days and she has turned brown andlooks like she is struggling allot. Today I did something terrible and cut her back completely. I thought maybe it would be better for the roots to give them time to relax in the soil without worrying about having to think about keeping its actual foliage and flowers happy. Please tell me I have not killed her forever.
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If your beautiful Blue has flowered once this season, you may have done a perfectly good thing; it may bloom again. We can't promise but cutting back after first bloom is frequently recommended. Fertilize her once again.
BTW, how far did you cut back: what do you mean by "completely"? It is advisable to cut only the flower stalk for reblooming.
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My delphiniums break off at the top whenever they flower. They look bad. Should I be planting them closer to the house or a similar wall for protection? Or do I need to plant them I clusters so they have each other to be more protected from the wind? They look beautiful, but grow very tall and then flower and then snap off just as soon as they are beautiful....I love the plant but feel like I'm doing something wrong....help?
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This is usually an indication that the plant/s need to be staked. See here for advice and options for doing that:
http://extension.psu.edu/plants/gardening/fact-sheets/gen...
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I am so sad! I was so excited to get my little Delphiniums home and planted to add a gorgeous blue to my little flowerbed. I wish I had read more on them though...I have a bazillion and one snails and they ate everything down to nubs! :( I now hate snails even more....is there a way to revive my poor Delphi-nubs?
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First of all you need to get rid of your snail problem. You can buy snail and slug bait with iron phosphate, which is usually successful. Go to our slugs/snails page at http://www.almanac.com/content/slugs" rel="nofollow">http://www.almanac.com/content/slugs for more information about getting rid of snails.
If the roots are OK the delphinium will grow new leaves.
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Great!! Thanks so much!
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I have the same problem with slugs. Sluggo works great for getting rid of slugs and it says it works for snails also.
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I just read about the green looper worms and delphinium. They strip mine almost every year. Sevin ant dust works, but I know it will kill the butterflies and bees. What else could I use? They truly will destroy it in a few hours, and start with the almost-blooms most years. ps I live in Wyoming.
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Hi, LuAnn,
These are nasty! But there is not much you/we can do. We mention handpicking and Sevin below. Here's a little more:
Our bast solution is actually a few we've researched. The University of California has several suggestions: http://www.ipm.ucdavis.edu/PMG/r52300311.html
This Colorado State pdf has several interesting pics and offers an array of deterents and worse for loopers on page 24 (the cabbage looper appears on p 15): http://webdoc.agsci.colostate.edu/bspm/Garden%20Caterpill...
A third solution seems to be self inspection and removal by hand, and explained here are neem (it stops them from feeding and so eventually they die), and suggests natural enemies: http://www.extension.umn.edu/garden/insects/find/caterpil...
If you happen on any additional or new sure-fire methods/ideas, please share!
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I'm so disappointed in the three Delphinium Grandiflorum "Summer Cloud". We live in Zone 9 according to another well respected site focused on Perennials only (Tampa, FL). When we purchased these at a large retailer, they were selling quickly so we snapped them up after being told it would be ok to leave in the pots as long as we kept the soil moist. About 2 weeks ago when we were finally able to plant in our flower bed all of the flowers had already fallen off. The plant instructions on this plant says "full sun", My flowerbed faces northeast and this plant gets full sun until approximately 1:00 pm (due to a bush planted approx. 2 feet behind it. Of course because we had just planted at first the soil was kept very moist and we used a moderately priced, nutrient enriched potting soil. This time of year is known for afternoon summer rain and I'm afraid the soil hasn't had the opportunity to dry out enough for it's taste. We've also experienced a change in color of the leaves to a light green, which was previously deep green. We planted at least 12" apart and away from other plants in our flower bed. It's been a while since the flowers fell off so I feel like an idiot when u refer to cutting off flower spikes. What does that mean? The whole stick? I don't know what I'm looking for & I do not want to cut the wrong piece. If it needs more prolonged sun exposure trimming the bush back isn't a problem but the actual plant is shock and although the soil has been pretty damp due to rain, it feels a little on the dry side. I'm puzzled. Can you help me to save this beautiful plant? As you can see I've tried to provide as much detail as possible. Thank you
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Keep the soil moist but not too wet and most delphiniums will grow well in full sun or light shade, so there is not need to trim your bush back. Cut the entire spent flower spike (stalk) back to where you see small side shoots.
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Do you know where delphiniums are from?
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Hi, May, The modern delph is the result of hybridization of species from around the world.
The word delphinium comes from the ancient Greeks whose word meaning dolphin (delphis) is a reference to the flower buds, suggesting that the buds resemble dophins.
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I have about 20 delphinium plants grown from seed in 9 inch pots in my greenhouse. Can I plant them out now oct5th or should I overwinter them in my greenhouse with a little heat and cover them with fleece to protect them from frost. Your advice would be gratefully appreciated.
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We are not clear where you live. In temperature climates: If you set out your transplants in October, they will flower in late spring to early summer bloom. In areas with cold winters, you would seed in April or May. Protect from frost by loosly covering with pine branches.
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I live in worsley Manchester, england
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Love the Almanac, wait for it to come out every year. I have two tall delphiniums that are about 15 years old. They always bloom late September, is there a way to speed this up?
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Delphinium can be divas. A September bloom is normal for some varieties, however, if you want to improve the odds, here are tips from local cooperative extensions:
1. They like to eat a lot! Give them constant feedings with compost-enriched soil and fertilize regularly.
2. Never let them dry out. You can keep the soil evenly moist and the roots cool by mulching to a depth of 3" or 4", either with a good organic mulch or with that compost. Water well during periods of growth (in spring and after it begins its second season's growth).
3. Plant it in areas where it gets some shade during summer afternoons.
4. Over the winter, cover them with branches or mulch to protect the roots from frost heaving.
5. We aren't sure where you live, but if you get extreme colds, pick varieties that can cope well.
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Hi it is the first summer having delphiniums in my garden in the uk, i planted late spring which maybe a little too late in the year. They did great but now in September have wilted and doubled over appearing dead. With next summer in mind do I cut back the delphiniums to just beyond the soil level and wit for summer growth next year ?? Your help would be great. Thanks
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Hi, Matthew!
You have not been waiting for a response since September, surely, have you? We check our pages frequently. Well, let's get on with it, in any case!
Our sources suggest removing the flower spike just below the lowest flower and leaving the foliage for future blooms. Smaller spikes may form near the base of the plant. Treat them the same way. Hope your dephs are dazzling!
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For many years, I had beautiful flowers; for about the last ten, I have an ongoing war with small green worms that eat the heart of the flower stalk before it has a chance to mature. If I sprinkle flour onto the stems, I can stop the damage up to a point; however, when it rains, the flour is gone. Does the butterfly/moth that lays the minute black eggs, do so in the fall or in the early spring? What can I do to prevent this?
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This sounds like a type of looper moth. You can do this:
Hand pick.
Control with sprays containing Sevin.
If larvae are under one inch, control with safer B.T. sprays such as Dipel or Thuricide.
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Hi I have had this plant for 6 yrs and it blooms beautifully and this year Calgary alberta has had aot of rain in june n july but it has been hot so far in august and now I see the leaves are brown so should I cut it down? I make sure its fertilized and not dry. should I let it keep growing as iv done for all these years or remove it
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There are several reasons for brown foliage on delphiniums.
Sometimes it's overwatering.
Sometimes it's lack of nutrients; delphiniums are heavy feeders and appreciate compost and fertilizer.
Towards the end of their cycle, the foliage simply turns brown as it dies down naturally.
If you are late in the season and the brown bothers you, you can cut them down at ground level.
You don't, however, really want to cut them down if the plant is still green as this will shorten the life of the plant.
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I planted 3 new delphinium plants a couple months ago. The leaves are now all brown around the edges. What is going on? Thanks for any help you can give.
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Brown edges are usually a sign that your plant is being overwatered or underwatered. Only water perennials if the rainfall is less than 1 inch per week. Soil should never dry out.
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I live in Southern Ontario, close to Toronto. I have a second-year plant that was doing wonderfully this spring. However, we've had a lot of rain the last little while and it seems to be fading fast. The leaves have turned yellow and wilted, the flowers are wilting and the stalks are doubled over as if it pain. I have hard-packed clay soil and have never had any problems with any of my other delphiniums. With all of this rain that we've had though, the area where this plant is, is boggy right now. Is my plant doomed?
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Yellowing of lower leaves followed by wilting is often crown rot, but there could be other problems. Delphs do need good drainage and lots of air circulation so they're not overcrowded so a boggy area will be problematic. Take a sample your local cooperative extension for a diagnosis and action plan.
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Hi, I am so new to gardening, I purchased my delphinum because it was beautiful, now I am reading about acidic soil and add lime????? Can you direct me to a site that will start at the beginning and tell me how to make soil?? Sorry to interrupt, you all sound so knowledgeable, I am in Texas, it sounds like I should have never purchased this plant, it seems they hate hot weather and thats about all I get here. How do I find what zone I am in? Thank you very much for all your advice.
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H, Sandra, Larkspur (Delphinium grandiflorum) is naturalized in much of Texas. However, they are fall-seeded annuals and they complete their flowering in late spring. Then you replace with hot-season annuals, such as periwinkles, celosias, or purslanes. As you said, they do better in places with fairly moist summers versus hot weather but there are heat-tolerant varieties in Texas and perhaps you have one! Just put lots of composted manure in their bed and make sure the soil stays well-drained as delphiniums hate wet soil. Don't let the soil get too hot. Stake them as they grow tall!
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Very informative info, I bought one 2 feet tall from a greenhouse 3 weeks ago and it is thriving. Now almost 3 feet tall with 2 flowing spires and a third growing. I'm in Denver and it's very hot now. I keep it moist with the ground soil damp. It seems to be working...
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Will Delphiniums winter over in Lake Tahoe in the Sierra Nevada's ?? We can have up to 20 feet of snow ... Many thanks
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Many varieties of delphiniums are winter-hardy up through Alaska and Canada. Mulch well with several inches of hay; some folks use pine branches to provide a loose protection from severe frosts.
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I live in northern BC , Canada. I have never mulched and my Delphiniums keep on coming back, bigger and more beautiful each year. The 3-4 ft of snow cover seems to insulate them very well.
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I’ve been growing delphiniums in New York City (on a very sunny terrace) for many years. I grow the delphiniums in fairly large clay or plastic pots--24 in to 30 in. diameter, using a combination of top soil, sand and compost. (I use soil and peat-moss with most plants, but peat-moss is acidic and delphiniums don’t like acid soil.) I buy the top-soil from a local garden center,and I find that it serves well for a great many years. I just add a little compost annually. In the past, my delphiniums always bloomed, but it took me a while to figure how to help them to make it through the winter. (We usually get snow--sometimes a lot of snow--2 or 3 times. And the temperature goes below freezing quite often.) By trial and error I learned: 1) to put sand around (but not on) the base of the delphiniums. I buy it from a hardware store) Otherwise, the delphinium crown is likely to rot. I also use some sand in Spring and Summer to protect them from rotting after heavy rains. THIS IS CRUCIAL (I put sand around columbine (aquilegia) for the same reason.) 2) After the first bloom, I cut them back, and they always re-bloom. 3) during spring and summer I give them low-nitrogen liquid fertilizer every 3 weeks. (the same fertilizer that works well for my roses) 4 When the ground freezes, I replenish the sand (as needed) and then cover them with evergreen branches from our Christmas tree. (I get extra branches from people on the street who sell Christmas trees--they charge very little. I have found that other types of mulch keeps them too damp. The evergreen branches let air circulate. I remove evergreen branches only when I’m quite sure that there will not be another hard frost. (here that is mid-March to mid April) After removing branches, I add compost, and as the plants begin to grow I begin to feed with the low-nitrogen fertilizer. None of this is hard--and in my experience, it’s fool-proof I’ve had 5-9 foot delphiniums survive 4 or 5 years, blooming twice each year.
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I planted dark purple Delphiniums (don't remember exact name) in my flower bed. The new flowers are coming out a very pale purple. What do I need to do to get the flowers back to the deep purple?
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There are a few theories as to why a delphinium might change color. If this is not the first season, it could be that the new flowers were from seeds of the parent plant, and if that parent was a hybrid, the seeds may exhibit traits not displayed in the parent, such as lighter color. If this is indeed the same plant, but the flower color has changed over one season, there is one theory that a change in weather, such as cold damage to the roots, or high temperatures, can cause the flowers to change color. Another theory is that the soil pH can affect color. However, this normally would not explain a color change over one season. Delphiniums usually prefer a neutral to slightly alkaline soil. We'd recommend checking your soil pH, and adding lime to an acidic soil to see if that helps. (Also, a delphinium flower will change color as it ages; but this wouldn't explain your flowers not having started out dark purple.) Hope this helps!
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I recently bought two flowering delphinium plants and planted one in a pot with potting soil that the garden store uses. It gets full southeastern sun. I watered well. Within two days, the leaves are withering and the flowers are drooping. I watered well again, no change. What could be the cause?
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The plant may show transplant shock and will recover. Delphiniums like cool weather, so if you have had the plant in full hot sun it would be wise to move it to a spot with afternoon shade until it recovers.
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After reading this I see I need to cut my plants back or stake them (due to the height). However I have been cutting them off, and putting them in water hoping for rooting to occur, and replanting them elsewhere. WHY DOES THE CUT DELPHINIUM NOT ROOT in WATER? Is there anyway to get the cut back piece to root? Please respond via email ASAP, as I have several batches in water that wont last much longer, and I need to plant them if this is possible...Thanks for your time. Lori, IL, USA
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You can propagate delphiniums by basal cuttings, but you need to include part of the brown callus material at the base of the stem. A 3- to 4-inch cutting in early spring or just after flowering is good. Then, you can place them in about an inch of water, or dip them in rooting hormone and place them in sand, perlite, or other light mix. Moisten the mix. If in rooting medium, place a plastic bag over the cutting (prop the bag up with stakes). Place the cutting in a bright, cool, humid area, about 50 or so degrees Fahrenheit. Rooting should occur in about 3 or 4 weeks. If your cuttings do not have that brown base to them, I'm not sure that they will root. You might try dipping them in rooting hormone and placing them in rooting medium to experiment.
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I have the same problem this year. Last year, I split my 3-4 year old guardian/black night? Dark blue delphinium in two large halves, so I could keep it healthy and more manageable (it was shorter last year when it bloomed and was expanding horizontally, and getting to heavy for the looser I had replaced it with, so it sank on the Back half and took the ground support box and stake with it!) I left the first half in the same spot. I used a tiny amount of clay with miracle grow when I covered it up and watered it. The second half I planted 4-5 ft. Away and used a milk water miracle grow solution to cover that half up. The original half hasn't come back this year. The transplanted half it back and as strong, healthy and tall as my new Pacific giant delphinium I planted last year. I planted 3 new pepsin isms decided the old one and left my second guardian blue/blue black night? 3 year old plant alone. Now, I Pacific giant delphinium is coming up and the second half of my old delphinium is coming up. I planted them all about 2 feet apart and I have a feeling that the huge second half of the old delphinium ended up really taking over and out growing the babies and older plant? Does this happen? All were doing good last year. Nice green foliage the surviving baby plant had even put out a tiny bloom but it's about 3 ft away from the huge second root chunk.????
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South western, NE, us. Zone 3
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Are they deer resistant? We have a herd that comes thru and eats on our clover...
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Delphiniums are rated "Seldom Severely Damaged" on deer resistant plants charts.
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I am searching for information on delphiniums and what variety might be best to try for my Midwest (Iowa) zone. It sounds like a dwarf variety might be less finicky! Thanks to everyone who comments.
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My mom lived in central Iowa and had a dwarf delphinium. The packaging stated it would have a life span of 5-7 years and would grow to approximately 2-3 feet tall. It grew about 4-5 feet tall each year (the first two were shorter) and lived over a decade. It probably would have gone longer had she lived to continue caring for it. Gorgeous plant each year and blooms lasted a long time.
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I have newly potted delphiniums putting out flowering spikes. Should I pinch back or allow to flower?
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With newly potted delphiniums, think out flower spikes if they are thinner than a pencil. Leave 1 to 3 spikes per pot. The more vigorous your delphiniums get, the more spikes you can leave.
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My favorite flower! When the first bloom finishes, I cut them back to the ground, and they bloom all over again, I even cut them back after the second bloom and they do it all over again. Always just as spectacular as the first time.
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In front of my house in UK (Kent), there are Delphiniums either side of the front door...was there when we bought the house 20 years ago and are still there. We are now in Bulgaria, where our Delphiniums which we sowed from seed 10 years ago, flower throughout the year and seems to love the intense summer heat....to our great surprise. When Delphinums appear not to be doing anything, or not flowering, dig them up and separate the roots, they are telling you they are rootbound...then you will have loads more to enjoy.
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Thanks for the great advice!
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This has been my second year with a delphinium plant bought from a garden centre This is its second year running producing no flowers, it is strong and healthy and green why is this happening
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Is your soil poor? Delphiniums enjoy amended soil rich in organic humus. Also, make sure the soil is well drained and not too heavy as this plant doesn't like "wet feet."
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Try scratching in a couple tablespoons of garden lime all around the plant, it sounds like the soil is also too acid.
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Does anyone know why my delphiniums did not come up this year? Are they gone for good?
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If your perennial is over 2 years old then there's a chance that you may need to replace them. Unfortunately, delphiniums are short-lived and generally do not do well after 2-3 years. Thank you for your interest in the Old Farmer's Almanac and our Web site.
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I've had a Black Knight Delphinium since 1998, a real beautiful eye catching display in front of my house, south of the porch entrance. Last week the plant is about a foot high, lush green, and I'm visualizing another year of beauty from this plant. Three days later its' leaves are eaten up. Just stems looking at me with a dead appeal. A search reveals greenworms all sizes. I picked them all, some 40 of them. What are they, where do they come from. Have not touched other perrennials next to this delphinium. My corner is naked and feel like I've lost a best friend.
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We feel for you. These worms are called green loopers (Autographa biloba). We don't always see problems with this insect but it seems to be very wide spread this year. They not only affect Delphinium, but also Geranium, Salvia, verbena, and other perennials. As you indicated, they should be hand picked, if not too extensive. The worms can be well camouflaged. In the future, there are some sprays you can use, if you're willing, including Sevin, permethrin, orthene. Or, if larvae are under one inch, B.T. sprays such as Dipel or Thuricide are effective. Follow the directions closely.
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Several years ago I planted a Blue Butterfly Delphinium in one pot on my patio. This has become one of my favorite flowers. I've become very acquainted with their foliage and each year I'm thrilled to find them coming back. They have thrown seeds and have naturalized, coming up against a rock wall or on the other side of the house, completely away from the mother plant. In fact, I dug up a wayward plant and transplanted it into a pot in my courtyard. That plant is thriving, too! This plant seems to defy all the recommendations for optimum care. We live in the mountains of New Mexico in an area plagued by high winds, but this little plant refuses to give in. I water it a couple times a week and fertilize it maybe a couple of times during the summer. It provides so much joy each year with it's gorgeous blue blooms. I wish I could have a yard full of it!
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Zone 10 low desert purchased delphinium this season. As they prefer a cool summer. If cut back and watered can we over summer in a protected area? Will come back or I treat them as an annual?