Growing Watermelons

Planting, Growing, and Harvesting Watermelons

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Age-Old Wisdom meets Modern Tools

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Everyone seems to love juicy watermelon in the summertime. Native to Africa, melons need warm temperatures (up to 80°F during the day) and a long growing season.

Gardeners in colder climates can still have success in growing watermelon vines by starting seeds indoors and choosing short-season varieties. Days to maturity range from 70 to 90, depending on the variety.

Planting

If you live in warmer climes, you can sow seeds directly outdoors, but wait until the soil temperature warms to at least 70°F to avoid poor germination.
Watermelon vines are very tender and should not be transplanted until all danger of frost has passed. (To be safe, wait at least two weeks past your last frost date.)
If you are in a cooler zone, start seeds indoors about a month before transplanting.
Amend soil with aged manure, seaweed, and/or compost before planting. Watermelons are heavy feeders. Learn more about soil amendments and preparing soil for planting.
Watermelons prefer a soil pH between 6 and 6.8.
Growing the vines in raised rows, known as hills, ensures good drainage and will hold the sun’s heat longer. Space the plants about 2 feet apart in a 5-foot-wide hill.
If you’re growing in rows, space 6 feet by 6 feet apart.
Watermelons like loamy, well-drained soil. Handle them gently when you transplant.
After you transplant, cover the plants with row covers to keep pests at bay. You’ll remove the row covers when you see both male and female flowers on the vine.
Find even more tips for planting watermelon in your home garden.

Care

Mulching with black plastic will serve multiple purposes: it will warm the soil, hinder weed growth, and keep developing fruits clean.
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.
If you choose to fertilize (and many do), make sure it delivers more nitrogen than phosphorus and potassium. However, after flowering begins, use a fertilizer with less nitrogen. We like to use liquid seaweed.
Pruning isn’t necessary, 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 a challenge to kill off a potential fruit).
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!
As fruit is ripening, prevent rotting by gently lifting it and putting cardboard or straw between the fruit and the soil.

Pests/Diseases

Harvest/Storage

Watermelons don’t sweeten after they are picked, so harvest time is important. They generally ripen over two weeks so keep your eye on them.

Dr. Bill Rhodes, professor of horticulture at Clemson University, offers the following advice on how to tell if watermelons are ripe:

Thump it. If the watermelon sounds hollow, it’s ripe.
Look at the color on the top. The watermelon is ripe when there is little contrast between the stripes.
Look at the color on the bottom. A green watermelon will have a white bottom; a ripe melon will have a cream- or yellow-colored bottom.
Press on it. If the watermelon sounds like it gives a little, it’s ripe. (Rhodes doesn’t like this method because it can ruin the quality of the fruit.)
Check the tendril. If it’s green, wait. If it’s half-dead, the watermelon is nearly ripe or ripe. If the tendril is fully dead, it’s ripe or overripe; it’s not going to get any riper, so you might as well pick!
Stems should be cut with a sharp knife close to the fruit.
Watermelons can be stored uncut for about 10 days. If cut, they can last in the refrigerator for about 4 days. Wrap tightly in plastic.

Recommended Varieties

‘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.

Wit & Wisdom

What’s in a name? Watermelon is 90% water.

The pumpkin vine never bears watermelons.

August 3 is National Watermelon Day (U.S.)!

Recipes

Reader Comments

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After harvesting the

After harvesting the watermelons, remove the plant. Clean-up the vines to keep insects and diseases from overwintering.

Beginner

How do I protect the watermelons from bugs since i have a few thumb sized melons started? And we're suposed to get 3 days of thunderstorms and rain will I have problems with splitting or anything else?

Compared to other crops,

Compared to other crops, watermelons aren't usually attacked by bugs. However, if you wish to be safe, a good control is the use floating row covers for the first few weeks; you must remove the covers to allow pollination of the flowers by bees. If you spot aphids under the leaves, spray with insecticidal soap. If you spot cucumber beetles, a spray application of rotenone or sabadilla is advised, but speak to your local garden center first. Avoid watering from overhead; water at the soil line. In terms of rain, make sure your soil drains well and the roots won't stay wet. If the melon splits, pick right away and cut out the split area.

How do I pick out the watermolen?

Do I pick it out of the vine or just cut the split out but still on the vine,and how do I cut out the split area?Thank You.

Pick the split melon off the

Pick the split melon off the vine right away so it doesn't go bad. Then just cut the split out of your fruit.

How do You prune the Plants?

How do You prune the Plants? Do I need to Pinch off the smaller melons ( size of a lemon)?

You do not need to prune

You do not need to prune watermelon vines. If you want to try and grow an extra-large melon for a competition, you could cut off the lateral vines (as the best fruit is often on the main fine), but there's really no need to prune watermelon vines. You could also pinch off some of the blossoms to focus energy on less fruit.

beginner 2

This my 2nd time growing melons (sweet babys)Last year I planted to late and the frost got to them. this year I planted in March and I have melon thats almost ready to pick and four more that are just beginning get larger. I been wating for the little curly do dad to dry up before I pick the first one. I'm also waiting to see the bottom of the melon turn yellow.I just read on this site to water less about once a week with two inches of water . please advise

Beginner 2

After the fruit stops growing reduce watering and stop all watering a week or two before harvesting. This allows the flesh to crisp and the sugars to concentrate.

beginner 2

Thanks for that advise. I got empatient and cut that first melon too soon,it was ony red around the seeds but still juicey, but I was still thrilled that I even have melons and will wait the full term for the next pick. I've got five more with more comining. Oh by the way I live in lancaster CA. thanks again

burned leaves

I have a lovely watermelon plant that produced a huge and sweet melon then about a week later has sprouted 12 new ones. They are about thumb size now. The plant overall covers about a 4x6 wide area. My son used a mix of soap and water to spray for some aphids (I think) and now half the leaves are burned to a crisp! Should I remove those leaves? Remove some of the fruits? Leave it alone? I will be so sad to loose this plant!! Also, the plant next to it is a smaller one and has bowling ball size fruit but it also is terrible burned! Not sure if the fruit will make it with so much damage!! :(

Burned leaves

You may have a fungal leaf disease. Symptoms begin as small yellow areas on the upper leaves and then turn brown. The entire leaf may wither and die. Remove the "burned" leaves and also remove about half of the small melons. The melons left will then have a chance to grow bigger.

burned leaves

Thank you! I'm pretty sure the burn is from the spray, not any disease, based on the location and quick show up (no yellow at all, just burned on the specific sprayed areas. I'll do the removal and see what happens! thanks!

watermelons

this is my first time growing watermelons im still unsure if im watering them enough are to much. And it has male flowers and i just saw a female flower that bloomed and has a ball on the bottom how long does it to take fully grow once the female flower starts will i see a melon grow? and do you know about pumpkin plants and honeydews?

watermelons

While melon plants are blooming and setting fruit they need 1 to 2 inches of water per week. Reduce watering once fruits are growing. If the female flower is pollinated the fruit will mature in about 60-90 days depending on the variety of melon and your weather conditions.

split watermelon

We did reaally well this year on watermelons we seen about 5 begin to grow but rotted off. However one did make it to about 4 pounds and when I check the garden it was split. Why is that? We have another growing and its about 1 pound and I wanna try to prevent spliting

Watermelons split when the

Watermelons split when the plant absorbs water too fast. The watermelon will channel that extra water to the fruits (which split).
Did you get extra rain? Or perhaps too much irrigation? Cut back and water consistently. Hope this helps!

split watermelon

Unfortunely the one pounder has split! We've been getting lots of thunderstorms lately and havent had to water the garden. Is it too late to start planting again?

my watermelon plant

My watermelon plant fully came out. Its only growing leaves. It sheds them once and while. Is it still alive or no. Please write me back Lilly

Hi, Lilly, On watermelons,

Hi, Lilly, On watermelons, you should see flowers on the vines first (not fruit). The first flowers to appear on the vines are male. The female flowers, which open later, have a swelling at the base that forms the fruit (the ovary). After bees pollinate these female flowers, the fruit develops. Poor fruit set in watermelons is usually a result of poor pollination. Bees are necessary to transfer the pollen from the male to female bloom. Common causes of poor fruit set include lack of bees for pollinating or cool, wet
weather that slows bee activity during bloom. Also, very hot weather or water stress could be a problem.

beginner

Hi! This is my first time planting a garden and we have watermelons, cantaloupe, squash, collard greens, cabbage and okra. My melons are all producing blooms but no fruit. We live in the south and the weather has been alot warmer earlier in the year and we haven't had much rain. I planted in late March and I water them every other day and use miracle grow once a week. Could you please tell me what we're doing wrong?

Melons have female and male

Melons have female and male flowers. Bees have to transfer pollen from one to the other. 1. Check your fruit. Sometimes it takes a few weeks to see the female flowers and you'll just see male blooms. The females have swelling balls (little melons) underneath. 2. If you have female blooms and no fruit, the usual reasons are high temperatures or lack of pollinators. Do you see lots of bees in the morning visiting the flowers? If you don't have bees, you could explore hand pollinating (and planting bee plants next year!).

Anonymous

thanks so much for your speedy response. i will continue to check my plants. i haven't seen many bees, only wasps and that could be because of the unusually high temps this year.

watermelons

last year I planted watermelons and I had vines galore but only a few melons developed but didnt grow very well. this year I have melons galore but they are spliting open before they are completely ripe. the heart is ripe and sweet but they are all splitting open. what can I do to stop this if I can. Its been really really hot here everyday in the 90's.

Watermelons Splitting

Cassie...This is happening in our garden as well!! If you received any good advice please let me know! Thanks :)

Even though it sounds like

Even though it sounds like it's been hot where you are, rain can cause melons to burst before they're ripe. It depends on where you are located, too. You may have poorer gardening conditions then you had previous years.

Varieties

I do like the sugar baby watermelons. My absolute favorite is the Georgia Rattlesnake variety. Charleston gray is good also. Never cared that much for those with other than red flesh. Thanks for the ripeness tips!

Testing ripeness

I have another option for checking ripeness. An older Hispanic man saw me struggling to pick out a watermelon at the store one day. His suggestion was to first look at the end opposite the stem end to see if the little "button" is black. That's a good thing. Then, he said to rub my fingers across the rind. If it feels sticky, it's ready. I haven't picked a bad one since he offered his wonderful advice!

I live in Goldendale,Wa. I

I live in Goldendale,Wa. I was out pulling goatheads from around our yard when I noticed another plant. Started to pull it and noticed what I thought was a cucumber. Turned out to be a watermelon. 5 grew to great tasting ones. I have 8 more growing. Never planted or expected them. Amazing