Planting, Growing, and Harvesting Watermelons
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Planting
When to Plant Watermelons
- In cool climates with short growing seasons, start seeds indoors 2 to 3 weeks before your last frost date. Plan to transplant seedlings into the garden about 2 weeks after that date or when the soil has warmed to at least 65°F (18°C).
- In warmer climates with long growing seasons, sow seeds directly outdoors 1 to 2 weeks after your last frost date, as long as the soil temperature has warmed to at least 65°F (18°C).
- Young watermelon plants can also be bought from nurseries. Plant these after there is no longer a chance of frost; they are very tender. Watch the local forecast and err on the side of caution! Consider laying black plastic over your planting area to warm the soil even more.
- Tip: Starting with young plants can result in an earlier harvest (usually up to 2 weeks earlier), so consider buying young plants, particularly if you live in a cooler climate.
Choosing and Preparing a Planting Site
- Amend soil with aged manure, seaweed, and/or compost before planting. Watermelons are heavy feeders, meaning they need soil that is fertile and has a high nutrient level. Learn more about soil amendments and preparing soil for planting.
- Watermelons do best in loamy, somewhat sandy, well-drained soil. They can struggle in soil that contains too much clay and doesn’t drain well.
- Watermelons prefer a soil pH between 6.0 and 7.5 (“slightly acidic to neutral”).
- Watermelons need A LOT of space—up to 20 square feet per plant. Their vines need room to sprawl, so plant them in a place where they won’t crowd out other crops.
- Growing the vines in raised rows, known as hills, ensures good drainage and will hold the sun’s heat longer.
- Plan to space the plants 2-3 feet apart in a 5-foot-wide hill.
- If you’re growing in traditional rows, space them at least 6 feet apart.
How to Plant Watermelons
- Sow seeds 1/2 to 1 inch deep outdoors or 1/4 to 1/2 inch deep in seed-starting pots indoors.
- Tip: To allow for more root growth, use larger starting pots than you would for most seeds. Also, consider using compostable pots that can be cut away or planted directly in the garden, as this will minimize the risk of damaging seedlings’ tender roots during transplanting.
- If direct seeding outdoors, sow 4 to 6 seeds per hill, eventually thinning to 2 to 3 seedlings.
Transplanting Seedlings
- Handle watermelon seedlings with extreme care when you transplant. Their roots are very fragile, so try not to disturb the soil when removing them from pots.
- After transplanting, cover the plants with row covers to keep pests at bay. Remember to remove the row covers when you see both male and female flowers on the vine, as pollinators will need to access the flowers.
- Find even more tips for planting melons in your home garden.
Growing
Watering Watermelons
- Watering is very important—from planting until fruit begins to form. While melon plants are growing, blooming, and setting fruit, they need 1 to 2 inches of water per week.
- Keep soil moist, but not waterlogged. Water at the vine’s base in the morning, and try to avoid wetting the leaves and avoid overhead watering. Reduce watering once fruit are growing. Dry weather produces the sweetest melon.
Fertilizing
- If you choose to fertilize (and many do), make sure it delivers more nitrogen than phosphorus and potassium, as this will encourage leaf and vine growth. However, after flowering begins, use a fertilizer with less nitrogen to instead encourage flowers and fruit. We like to use a seaweed-based fertilizer.
Flowering and Fruiting
- Vines produce male and female flowers separately on the same plant. They often begin producing male flowers several weeks before the females appear. Do not be concerned if the male flowers fall off. The female flowers (which have a swollen bulb at the base) will stay on the vine and bear fruit.
- Blossoms require pollination to set fruit, so be kind to the bees! Learn how to support pollinators in your garden.
- As the fruit is ripening, prevent rotting by gently lifting it and putting cardboard or straw between the fruit and the soil.
General Watermelon Care Tips
- Mulching with black plastic or straw around the plants will serve multiple purposes: it will warm the soil, hinder weed growth, and keep developing fruits off the soil.
- Pruning generally isn’t necessary for watermelon plants, but vine productivity may be improved if you do not allow lateral (side) vines to grow and stick to the main vine. When the plant is young, just cut off the end buds as they form (before the side shoots become vines). You can also pinch off some blossoms to focus the energy on fewer melons (though it’s challenging to kill off a potential fruit).
- ‘Sugar Baby’: 80 days to maturity. Produces 10-pound melons with bright red flesh. This variety of smaller fruit can be planted just 4 feet apart.
- ‘Sweet Beauty’: 80 days to maturity. A 2004 All-America Selection. Bears 6-pound, oblong melons with red flesh.
- ‘Golden Midget’: 70 days to maturity. Bears petite, yellow-skinned 3-pound melons with pink flesh. Good for Northern gardeners.
Catherine Boeckmann
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I live in Lake Wales Florida for the first time in my life I have my first Garden ever it's little but it's plenty for me I'm looking to learn and grow with my garden well here I go I have 3 different types of tomato plants three different types of peppers spinach kale two different types of lettuce romano and iceberg green zucchini green beans peas 2 onions broccoli celery one strawberry plant and one watermelon pod.. in my kitchen window I have for pots I have Greek oregano basil and two different types of Ceylon through the leaves a different it was growing fine now that it's in the window getting direct sun my leaves are turning yellow could you kindly please help me..the soil here down south is different than up north I mixed the ground with cow manure plenty of it and potting soil as well I also water them with some type of fertilizing food like one teaspoon to a gallon of water so I was just wondering am I taking care of my garden the right way how do I continue to keep it healthy... thank you for your time looking forward to hearing from you with happy gardening smiles.
Most vegetables and herbs grow best in fertile well-draining soil. It’s very important to amend the soil with organic matter like compost and/or aged manure. Each vegetable has different requirements for sun/shade and water/fertilizer. If you are using compost and manure you don’t need to use a lot of fertilzer. We suggest that you click on our vegetable/herb pages to read more about the specific growing conditions for each plant. We wish you luck with your first garden.
Question: I planted some sugar baby watermelon in little starter cups. There are a few that sprouted and they are yellow. Are they too wet? I have others that have sprouted dark green, as they should be. Help please!
Thank you in advance!!
Sir, I don't understand the planting space between column and rows. Can you explain?
I've started watermelon seeds in Jiffy peat pellets & at this time they're about 4". I've been preparing the soil for transplant. Here in So Tx the dirt is like clay. I've mixed in compost & potting soil to an area about 4'x6'. The seeds are Sugar baby. Do I need to transplant the seedlings asap, if so I hope my soil is satisfactory.
My first time growing watermelon and I put the seeds in a 20 gal container next to my garden. I am expecting the vines to grow from the container into the garden. Right now my entire garden is covered in black paper to keep the weeds down. I was hoping that the watermelon will just grow over the paper. Does the paper need to be removed so the vines can grow in soil or is there enough soil in the container that the vines will produce. I live in Florida so it is already warm and I wonder if the dark paper will be too warm for the watermelons. Thanks in advance.
Bob
A 20-gal container is big; minimum 5 gallon is usually recommended. Does it have drainage holes? It will need a lot of water through the season, and as with any container, you want that water to be able to drain out.Water it daily when temps are below 80°F; twice when above.
Black paper is generally used to warm the soil and, as you say, warm the soil and keep out weeds. But your plant’s primary soil—the soil it’s growing in—is in the container. Do you have a sandy, loose composted soil mix in the pot? Not dirt from the ground (such as under the black mulch), right? Watermelons like a loose mix to spread out in.
Watermelon vines need something to cling to (when planted on the ground, this might be other plants or vines or even grass). You should expect to provide mesh or trellis or something to help guide your vines. We can’t be sure what they will do on the paper. The vines do not grow into the soil; the plants roots grow into the soil. Not sure if this answers your question.
People often grow watermelons in containers because they lack the ground space, and with containers being relatively small, they choose varieties that produce small fruits. Consider the requirements of the seed variety you choose. (The size of your container makes us think that you’ve growing a large one.)
let us know later in the year how all this works out. Good luck with it!
The container I am using is one that I had from a plant I purchase and planted in the yard so it has good drainage. The soil I put in the planter is just Miracle Gro potting soil. I have some rabbit fencing I could lay on the black paper for the vines. There are two plants in the planter. Do you think I will have to add fertilizer as the growing season progresses?
Plan to fertilize with a general all-purpose produce when seedlings emerge, making sure to get it to the roots (use liquid, not solid fertilizer). Liquid seaweed fertilizer can be applied after leaves appear and once flowers emerge. Watermelons also benefit from nitrogen when vines begin to take off and when fruit appears. Use a 33-0-0, well diluted. Stop nitrogen applications when fruit has set and replace it with something high in phosphorus and potassium. Read more about these essential beneficial ingredients—and more—here: http://www.almanac.com/content/preparing-soil-planting
Your write up is so educating, thank you. I'm interested in watermelon farming, how can I learn all I need to know about this? E.g . Best variaties of water melon, Favourable environment, Maturity period, Best farming seasons, Best fertilizers to be used, Planting methods e.t.c.
I live in Nigeria. I'll really appreciate your help in this regard. Thanks.
Ambrose Alufah
