How to Grow Phlox: Planting & Care Guide for Phlox Flowers

First time growing so would appreciate your reply

Hi Edna,

It is a good idea to divide your phlox every 3 to 4 years. It will reinvigorate your plants.

Since tall phlox produces flowers in mid- to late summer, you can divide it in the spring before new growth begins. But since that time has already passed, you can divide it in the fall after the flowers have faded, but well before the threat of frost to give it time to establish.

When dividing, make sure each division has at least 2 or 3 shoots with roots attached.

Hi, Sheila, We do not recommend using landscape cloth for almost anything. We assume that you would put rocks on the landscape cloth. If so, that may appear to work for a while, but when weeds break through or become embedded among the rocks and cloth, you would have a real job trying to eliminate them. Note, too that phlox spreads by seed, so some seeds will land near the mother plant and some could be blown a distance from it, which means you could have phlox where you least want or expect it.

Instead we recommend mulch. Of course, phlox and other plants can/will take root in mulch; the solution is really to weed them out. 

I planted one of these in my garden this spring, and it just won’t take off. It looks like it’s about to die. I don’t know what to do. But after reading the comments, I think I might be over watering it so I’m gonna back off the water and see if I can bring it back.

You can trim down the same way and simply move the pots into an unheated garage. Do not water. It goes dormant. The tall type won’t grow as a houseplant.

Hi, Judy,

You might have some luck rooting the stems. Try it. It could take a couple or a few weeks; hard to know. In the spring, you can also divide the existing plants. Each division should have 3 to 5 vigorous with roots attached.  Plant them with the crowns an inch or so below the soil surface. To ensure that the remaining plants survive think about "fencing" them: Get a quart container such as a deli might put potato salad in. Cut off the bottom. See if you can drop the round tube over the plant to ground level. If you can't, slice the side of the container and then put it around the plant. It might help to deter rabbits.

We hope this helps!

I love to root in water, my blue phlox clippings start sprouting roots in a week or two but I leave them my kitchen window longer.

Hi Jane, just reading up on phlox and saw your concern. I purchased a couple of phlox plants today and in researching, I read that your phlox could be doing well for ages and then all of a sudden it seems as there are hardly any flowers being produced. The reason is that it is time to split the phlox up. Once this is done, you will be back to having even more blooms. Hope thats right and answers your question.

I would love to know how to keep the tall wisps of grass out of my creeping phlox, too. Last year, I tried Preen Weed Preventer, but that didn't stop the growth of the grass.

pruning plants; I've heard Ralph Snodsmith; Horticulturist say; "anytime u have brown leaves or stems; prune the brown leaves and stems back";

Creeping phlox will creep towards sunlight. On a sloped or vertical surface, plant creeping phlox at the top so that it can hang and creep with the aid of gravity. 

If they normally perform well in those spots, it's likely just the lack of water that's causing issues. If you're able, give them some supplemental waterings in order to get them through autumn. Hopefully, next year will bring a bit more rain and they're spring back to life!

Tall garden phlox tends to spread by seed. To prevent this in the future, remove flowers once they've started to fade and before seeds are produced. If you pull out the unwanted phlox and are able to get most of the root system, it should not return.

if you mean that the stems collapsed it could be that they are getting too much water from you or from Mother Nature. If you don't think so, it may be that the soil is retaining water; it is not running off or being absorbed into the ground. ANd/or it may be that mulch is retaining moisture and is up against the stems.

Cutting back is generally recommended earlier in spring, but do it now if this is your best time. Also see above.

See the info at the very top of the page to the right of the picture of phlox and read the recommendations.

1. Can You Grow Phlox in Pots? Yes, you can grow phlox in a large pot, keeping it outside in spring and summer and in an unheated garage or shed in the winter. You'll just want to make sure that the potting soil doesn't dry out entirely at any time; while in winter storage, keep it lightly moist but not as much as you would in spring/summer, while the plants are actively growing. 

2. How Do You Deadhead Phlox? By using a technique called deadheading, phlox can be encouraged to keep producing flowers. Deadheading simply involves snipping off the top cluster of flowers that have finished blooming, while leaving any lower flower buds alone. These lower buds will appear just above the leaves. When making the cut, leave about half an inch of stem above the highest buds. 

Phlox transplants quite well, so if you can take a chunk of the existing plant that has some roots on it, you shouldn't have any trouble getting it to grow on top of the wall!

Assuming you are transplanting them from their nursery pots to a container or the soil, there is a phenomenon called "transplant shock," which may occur shortly after you transplant a plant into a new environment, especially if the new environment has very different conditions (more light, more heat, less water, etc.). The plant may drop its flowers or some of its leaves in order to prioritize producing new roots. It sounds like this is what's happening with yours, made worse by the heat of summer. After it is planted and settles in, the phlox should produce new flowers. Do yours? 

Alternatively, it could be that the phlox is not used to so much sun and heat. It may have lived a more sheltered life in the nursery, so perhaps try keeping it in partial sun for a week or so when you first bring it home, then move it into full sun.

WHY don't you say how deep to plant tall hardy phlox??

Spring is the best time to plant creeping phlox, so now would be fine. We're about a month from summer, officially, so this should give it time to become acclimated.

Phlox is pruned back AFTER spring blooming season to help maintain the form you prefer. This is generally late May (after flowering).You want to make sure there are no buds left to open before you begin this process. Using garden shears, cut back the plant by a third or half. Do this annual after each spring blooming season and you'll get back on track.

We're in the Northeast. It's late May and phlox is already about 27-30 inches high no buds yet . Last year they got too tall. Should we cut back now to contain them.flowers were lovely but the height was unattractive.

Cut back phlox after bloom. Make sure all buds have bloomed. Generally, the time to cut back is late May (after bloom) to mid-August. 

Hi Jeremy,

Depending on the type, you would plant spring-blooming phlox in the fall and fall-blooming phlox in the spring. Plant fall-blooming phlox in your region in the spring at least after the last frost of the season. We hope this helps! 

The Phlox I have is pink and white(Phlox paniculata ). It is quite tall--3.5- 4 feet. I just bought a pound of seed on line and plan on starting lots of new Phlox plots. The deer are not at all interested in it, so that is a plus! The plants have been coming back every year for many years; I just love em! I am careful to gather the seeds before the birds get them-- I buy plenty of seed for the birds all winter long. I have moved them around and they seem hardy, requiring little or no care.

Apparently there are some pretty tall phlox varieties: Border phlox Phlox paniculata "David" is one; Mile High Pink Phlox is another; Caspian, Hesperis, Kirmeslandler, Old Cellarhole, Robert Poore, Russian Violet are others. Heights of these mention range from suggested 5 feet to about 6 feet. It may be that you have perfect conditions that inspire yours to reach even higher! As for how they got into your garden...an animal or bird may have transported the seed but it's impossible to know for certain.

You should be able to achieve that effect, if the conditions—soil, sun, and water—are appropriate. Take note of the variety, ask questions about height, and you will not be disappointed. There are many varieties from which to choose ("ground cover" will not give you the desired effect).

You should have no problem. Phlox are perennial. Take note of the guidance above and be prepared to give it time to settle in.

The general guidance for propagating phlox seems to lean toward stem cuttings dipped in rooting stimulant powder.

The Virginia Cooperative Extension explains in detail:

Generally, tip cuttings are easier to propagate than root cuttings. Select second growth of phlox for cuttings. Make tip cuttings 3 to 6 inches long. Treat the base of the cutting with a root stimulant. Leave all foliage on the cutting except the part that will be below the soil line. Insert one cutting per peat pot. Place peat pots of tip cuttings in a lightly shaded place. Cover with a sheet of clear plastic. Check regularly to make sure the cuttings do not dry out. When cuttings do not pull easily out of the soil, they have begun to root. Make holes in the plastic sheet to increase the exposure of the cuttings to the air. This will harden the cuttings. Every few days, enlarge the holes or make new ones.

You can also make root cuttings of phlox. Dig the plants in late summer after they have bloomed. Select pencil-sized roots; cut them into 4-inch sections. Put each piece in a peat pot. Prepare a tray of peat pots as for seeds, except the soil mix should be 2 parts sand, 1 part soil, and 1 part peat moss. Water thoroughly.

This just happens sometimes. Is your phlox getting enough sunlight? It needs 4 to 6 hours of DIRECT sunlight at minimum. As you mentioned, you can also fertilize. Applying Miracle-Gro one time per month should be ample. The only other thing we can think of is crowding. And we have read that lack of pollintors can be a cause.

I live in MI in zone 5-6 and my David phlox is just now starting to bloom, which is late for them. Our weather has been very changeable and we have had a lot of strong winds. They are looking pretty good now.

If you are new to either craft, you might check out a book or two at your local public library, or read online about materials, techniques, and equipment involved. Sometimes you can also find classes on each craft; the experience is fun and really helps one get a feel for what the craft is like. Oftentimes, you also learn invaluable tips from the instructor that save effort or cost, or produce especially beautiful results. For dyeing, you might need to use a mordant, such as alum, to set the color. There are also natural mordants such as sumac. You might be interested in this site about natural plant dyes:
https://www.fs.fed.us/wildflowers/ethnobotany/dyes.shtml
Perhaps you might also enjoy reading about this craft with natural plant dyes that our staff tried one time:
http://www.almanac.com/blog/blogs/dyeing-easter-eggs-natu...
Have fun!

Hi Mary,

Yes, you can transplant phlox plants from a greenhouse from now until early fall. They will establish before the fall frost and continue growing in the spring.

Hmm. We can't be absolutely certain what the problem might be. Some say that overwatering (even if it's rain) could be harmful to phox. Then we learned about Lopidea davisi—a bug that feeds on phlox and overwinters in dead phlox stems. You might want to contact the nursery and see if they will exchange the plants for you. If this is the problem, you need to cut back and dispose of infested stems and leaves. Apply insecticidal soap to the upper and lower sides of leaves and follow with a light horticultural oil. There is a picture of the bug and a few of infected plants here: http://www.missouribotanicalgarden.org/gardens-gardening/...

We hope this helps.

I planted 2 Phlox last year, they were beautiful all summer long...now is mid May and they have not come back yet...should I have any hope? or are they most likely dead? :(

First, make that kitS, Paul. You'll need more than one. As to how to move forward, it seems to us that it depends on how much time you have. Kits require preparation and monitoring, then transplanting. Broadcasting . . . not nearly so much.

Hi Vicki,

Good question! Phlox grows from the main planting and can be stimulated to grow new shoots with mild trimming. Mulch up to the roots, but keep in mind that the ground will be covered over time and excessive mulching is not necessary. 

We hope this helps!

According to the University of Hawaii cooperative extension, Phlox mhnlata which is commonly called Moss Pink is a good choice for warm-weather climates. this is an "evergreen mat-forming perennial that grows to 6 inches high with l-inch-long linear leaves. The .75-inch flowers range in color from red-purple to violet-purple, pink, or white. Easy culture in any garden soil but best with abundant moisture and fertilizer in neutral and alkaline soils, cooler areas with full sun. Rapid cover. Many listed cultivars available."  I'd ask local nurseries about this phlox or call your local cooperative extension for more on-the-ground advice.

At this point/stage, Jimmie, the most important part of the plant/s is underground. You will not hurt them by cutting them back now.

Unfortunately, bringing it into the greenhouse won't extend the bloom time--its DNA dictates when it blooms, sets seed, and dies back, and there is nothing to be done to change that. But you could try growing a variety that blooms later in the summer, such as Phlox paniculata 'Pink Flame', a dwarf cultivar that grows to be 12 to 16 inches tall.

A hard frost is probably not too far off. Go ahead and get them in the ground (that is a better option that trying to keep them indoors), water well, and insulate them with a heavy layer of mulch around the crown. Or you could plant them in a container, water, mulch, and tuck them up against the house or somewhere with a bit of protection; then transplant them into the garden in the spring.

Nature's surprises present wonderful opportunities. Sure, clip off a couple/few of the babies and set them in water to see if they sprout. Or use a bit of root powder (available at almost any nursery/garden store) and set them in dirt (per the directions on the package).

Let us know how this goes!

You can transfer potted phlox into the ground any time during the growing season, right up to early autumn. Set the crown of each plant about an inch and a half below the soil surface.

Hi Dejra,

Phlox typically likes full sun. It will tolerate light shade, but it will be less vigorous and won't bloom as well. There are three species of phlox that are said to be deer-resistant: woodland phlox, garden phlox, and creeping phlox so it doesn't sound like phlox will lure them away from your 4 o'clocks. Try instead to protect them with netting.

Hi Lennie,

Yes, that is doable. Phlox species grow in Florida. Bear in mind, they prefer moist soil and part shade--their native habitat is deciduous woods and bluffs.

Well, the variety might be the key here. "Bare root" is not a type of plant, it's simply a descrip of the condition in which you received it, usually shipped, but several types are noted above (see "growth requirements") and each requires a slightly different moisture level. Based on that, it could be that your moisture/drainage conditions are not suitable. But consider this, too: are your plants getting at least 6 hours of sun? Phlox thrive in full sun; an insufficient amount of sun, even partial shade, will hinder blooms. If this is the case, you should move them. Also, over-fertiliziing, esp giving these plants too much nitrogen, can cause them to grow great stems and leaves but no flowers. A soil test will give you a clue about your soil quality. Does any of that sound like your situation? Phlox do not ask for much. Here's hoping something here brings these beauties into bloom.

My phlox and blazing star were eaten last year by rabbits or deer. This year I bought the deer and rabbit repellent, so it is a wait and see until they bloom. So far, they have left them alone. This repellent is called Liquid Fence. It has egg and garlic in it and can be purchased at Lowe's or Wal-Mart. As for them falling over, did you check their roots? Could be a gopher problem underground. Good luck Sue!

Did you ever figure out what was causing the breakage. I have the same problem with mine. There are not animals doing this. This is the plants fourth year. They are gorgeous with beautiful blooms, but they are brittle. I live in northern IL. Thanks!

It's not too late to plant the seeds. You may not have as many blooms this year but the plants will have time to grow and get established for next year.

Well, nursery people in your own community usually know best about local conditions...certainly better than we here in New Hampshire might.

The Missouri Botanical site (not either of our neighborhoods, but a pretty reliable source: http://www.missouribotanicalgarden.org/PlantFinder/PlantF... ) suggests on its link in parent that creeping phlox does best in zones 3 to 9 (which appears to include Louisiana; see here: http://planthardiness.ars.usda.gov/PHZMWeb/) and likes full sun but "generally appreciate[s] some dappled sun in the hot summers of the deep South."

And that's without getting into your soil quality etc., see above this page.

The only other thing we would advise is to return to the nursery and see if they can recommend anothe rplant that will accomplish what you want...just in case the creeping phlox becomes sleeping phlox.

All the best—

Hi Theresa,

Phlox is perennial and will survive winters in Michigan. You can plant the phlox in a container and then transplant it out into the garden. Please see our planting advice at top of this page.

I have had carpets of creeping phlox for years. this year I have lost 90% of it and wondering if it was winter kill and or voles. very little growth on the tips of the shoots. looks like dead hay laying everywhere. can I cut it back to try to force new growth or do you think I have lost it????

The common tall phlox will not do well in southern Florida, too warm and humid. There is a wild native phlox that will grow well. See http://www.fnps.org/plants/plant/phlox-spp.

The phlox is probably reseeding and the offspring are not true to type. 

You may want to wait. The best time to divide phlox is late summer or early fall.

Is your phlox getting enough sunlight? It needs 4 to 6 hours of direct sunlight at minimum. Do you fertilize?  Applying Miracle-Gro one time per month should be ample. If your phlox does not bloom next year, you may want to rip it out and begin anew.

Are they root bound?

Hi Connie,

If you have not divided and replanted the phox recently it may be overcrowded. It's recommended that you divide the plants every 2 to 3 years.

You can deadhead the phlox and you may get some new smaller stems off the main stem and sometimes it will rebloom. In the fall you can dig up the plants and see if you can divide them to create more plants for next year.

The seeds will develop at the same location as the flowers. Once a phlox flower has been pollinated/fertilized, the petals will fade and dry and that part of the plant then will form a seed capsule (aka seedhead, seedpod), which is the "fruit." Inside this capsule are the seeds. Different phlox species may have different forms of seedheads, but see the photos below to get an idea. Note that phlox have seed capsules that, when the seeds are mature, will split open (sometimes "explosively") to release the seeds, so if you see an open capsule, the seeds may already have been distributed. Hope this helps!

http://commons.wikimedia.org/wiki/File:Phlox_paniculata_f...

https://www.flickr.com/photos/blueridgekitties/5944698731/

https://www.flickr.com/photos/blueridgekitties/5944697839...

http://www.friendsofthewildflowergarden.org/pages/plants/...

https://www.minnesotawildflowers.info/flower/prairie-phlox

http://www.friendsofthewildflowergarden.org/pages/plants/...

Not sure how old this post is but my phlox got a heavy amount of snow and salt on it and came back just fine. Doesn't lend an answer to your sand question but they'll be fine. They are tough flowers.

Creeping phlox is a hardy perennial with some salt tolerance. In the early spring use the garden hose to spray the area with water and wash off as much of the salt and sand left after the snow melts.

Hi Mercedes,

Most phlox paniculata varieties are cold hardy in US zones 3 to 8, but there are a few varieties that are tender. It's good practice to cut the stems back before winter like you did. Don't give up yet. The plants may still be OK and surprise you with new growth.

Sounds as if you ordered bare-root plants--and yes, they will look dried out and perk up in the growing season. Phlox is usually planted in the spring. It can be planted in fall in early autumn. Fall-planted phlox are more subject to frost heaving, though it's not unusual to receive mail-order plants too late in fall to be planted safely. If you plant them, be sure to add 4 to 6 inches of mulch (hay, pine needles, chipped leaves) as soon as the soil freezes to protect your plants and give them the best chance.

Hi, Aubrey, This all sounds normal... It's fall: Phlox is a perennial, it will die back in autumn (as daylight lessens and cooler temps set in). Cut the plants back to about 3 inches (too much more might damage the crown). Remove debris from the bed to discourage diseases. When it's clear that the warm days are behind us, lay on a protective pillow of mulch. (Doing this too soon, while the soil is still relatively warm, might trigger regrowth.) Since this is the plants' first year, leave them intact, but in future consider that autumn is a good time to divide plants.

Hope this helps!

Do the leaves of your phlox appear to have a whitish dust on them? Phlox is quite hardy but also prone to powdery mildew if it's been humid or wet. It's fairly normal and doesn't usually hurt the plant. You can throw away the affected foliage and pinch off any other affected leaves; spray the rest of the plant with fungicidal soap.
If your phlox doesn't have powdery mildew, sometimes leave drop can happen with older phlox as the summer progresses. This is a signal that you may need to divide your phlox and and replant in compost-rich soil.

It sounds as if you may be cutting the phlox too far into its bloom. Cut the phlox when a couple buds are showing color and one bud starting to open. Also, cut flowers in the morning. Hope this helps!

I would like to know if phlox require a chilling period to grow. I live in the tropics. Thanks, BLG

Most phlox varieties will rebloom if you deadhead them. Just cut off the spent flowers and you should see new growth from the main stem.

Do you live in the Southeast (Alabama, Mississippi, etc)? There is an invasive plant called lovevine that is orange and it doesn't take long to completely choke the hosts that it covers. Google some pics to help identify.

Phlox paniculata 'Victoria' will grow well in Texas and reaches a height of three feet.

why are the leaves on my phlox turning yellow and dieing?

I have different colours off Pholx plants they have bloomed every year, this year I have healthy plants but no blooms! help

I live just west of Bloomington, Indiana and this July 2014 I had a volunteer phlox come up by my neighbor's back privacy fence. It's around 3 ft. tall, and I sure hope it spreads. Might you need to separate yours so they bloom? Just guessing. Good luck!

Yes, I have the same question as I too am new at this. My blooms are almost gone and I don't know how far to cut off. I love my blooms and want to do it right.

You can still plant your phlox. It will likely grow new stems from the roots.

You can also try to root the broken stem. Shorten the stem to about 3 to 6 inches long with 2 to 6 leaf nodes. Cut the stem with a sharp knife at an angle just below a leaf node. Remove flowers, buds and lower leaves. Plant the cutting in a pot with equal parts moist coarse sand and vermiculite or perlite. Make sure the lowest leaf node just above the surface.

It's hard to tell what caused the plants to die. There are three common diseases of phlox. Oedema causes rusty blisters on leaves and petals. Parasitic nematodes (roundworms) turn foliage and stems brown and mottled. Powdery mildew creates a dusty white covering on leaves, stems and flowers.

Hi Anju,

The phlox should be growing by now. Are the plants brown with now green showing? If you decide to replant amend the soil with compost and a bit of sand for better drainage.

You can cut the phlox back for bushier growth. Early in the season May/early June cut about half off. If you want to experiment cut some less and some more to see how high they will grow.

Good for you! Phlox are so pretty! A lot of this has to do with what type of phlox, where you are, and how much salt we are actually talking about, but in general most phloxes are at least moderately salt tolerant. We have about 15 feet of creeping phlox along our New Hampshire uphill (well, from the bottom) driveway, the bottom end of which is about 8 feet from the road. Over the course of the winter, we shovel and/or snow blow at least a moderate amount of road salt on the lower part of the phlox bed, and it never seems to be any the worse for wear. Give your plants some help. Make sure the bed is well drained to make it easier for any salt to leach through and not hang around. Ask the maintenance men to shovel in the other direction if there’s salt around—maybe bribe them with a muffin a month or whatever? If you foresee a period of above-freezing temps with at least some sun, you can wash salt off your phlox, too—that can be of help. Finally, consider doing a little test: Cover a small part for the winter and see if it makes any difference. Then you’ll know what to do the next year. Good luck!

Phlox is planted in the spring. Whatever your space, look at one plant for every 1 to 2 feet, depending on the variety. 

deer and rabbits may eat the phlox

It's best to plant phlox in the spring as soon as the soil is workable. As your area gets very cold in the winter, be sure to add 4 to 6 inches of mulch in the fall as the soil freezes. 

Trim back the plant(s) it finishes flowers. Then, fertilize with a general (e.g., Miracle-Gro) fertilizer. A bit of fertilzer every year would not hurt, and some sources suggest shearing the stems one-third to one-half after flowering every year to encourage new foliage—and possibly a second flower display.

Cut out the woody stems in the middle that no longer produce flowers. Tender new stems will replace the old ones. It's a good practice to cut off any spent flowers in the summer to encourage new growth and prolonged bloom.

It all depends on what type of phlox you have. Most phlox varieties are cold hardy and tolerate winter chills. Find out what kind of phlox you have and see if it is cold hardy in your zone. If the plant is doing well you can plant it in the ground in the spring.

Our guess is that your phlox bloomed, went to seed and dropped the seeds in the soil. The new plants grew fast enough to start blooming before the end of the season. You can check to see if the phlox bloomed on the old stems or new stems.

A "perennial" plant is one that grows for multiple years so, yes, it will should come back in the spring. Here is the definition: http://www.merriam-webster.com/dictionary/perennial">http://www.merriam-webster.com/dictionary/perennial

To avoid this issue, just deadhead your phlox before they go to seed. This is good practice (not just because of your cat); the little seedlings tend to crowd out the mother plant over time.

Phlox are perennials.

there is an annual phlox one can purchase often in multi colored mix seed packs. They grow to about 12-18" tall and if trimmed of flowers going to seed will continue flowering all summer.

Is your phlox getting enough sunlight? It needs 4 to 6 hours of DIRECT sunlight at minimum. As you mentioned, you can also fertilize. Applying Miracle-Gro one time per month should be ample. If your phlox does not bloom next year, you may want to rip it out and begin anew.

Deadhead the dead bloom a quarter-inch above the next bud. You can use a pair of snip with sharp scissors or hand pruners. 

Sprinkle 10-10-10 fertilizer around the plants and mulch with compost or other organic mulch to keep the soil moist and weeds down.

yes, they are a spring blooming plant. Mine was all bloomed 70 degrees one week, snow the next, still perfect. Dont worry too much about them, once they start to grow they grow pretty rapidly.