Botanical name: Citrullus lanatus
Plant type: Fruit
USDA Hardiness Zones: 3, 4, 5, 6, 7, 8, 9, 10, 11
Sun exposure: Full Sun
Soil type: Sandy
Everyone seems to love juicy watermelon in the summertime. Native to Africa, melons need warm temperatures (up to 80 degrees during the day) and a long growing season. Gardeners in colder climates can still have success in growing watermelon by starting seeds indoors and choosing short-season varieties. Days to maturity range from 70 to 90, depending on the variety.
Planting
- Amend soil with aged manure or compost before planting.
- Growing the vines in raised rows, known as hills, ensures good drainage and will hold the sun’s heat longer.
- If you are in a cooler zone, start seeds indoors about a month before transplanting. Watermelon vines are very tender and should not be transplanted until all danger of frost has passed.
- If you live in warmer climes, you can direct sow seeds outdoors, but wait until the soil temperature warms to at least 65 degrees to avoid poor germination.
- Space the plants about 2 feet apart in a 5-foot-wide hill.
Care
- Watermelons like loamy, well-drained soil. Handle them gently when you transplant. Add lots of compost to the area before planting and after planting.
- Mulching with black plastic will serve multiple purposes: it will warm the soil, hinder weed growth and keep developing fruits clean.
- Row covers are a good idea to keep pests at bay.
- While melon plants are growing, blooming, and setting fruit, they need 1 to 2 inches of water per week. Water in the morning, and try to avoid wetting the leaves. Reduce watering once fruit are growing. Dry weather produces the sweetest melon.
- Once fruit begins to grow, prune end buds off vines. Your plants may produce fewer melons, but they will be larger and of better quality.
- Vines produce male and female flowers separately on the same plant. They often begin producing male flowers several weeks before the females appear.
- Blossoms require pollination to set fruit, so be kind to the bees!
Pests
- Aphids
- Cucumber Beetles
- Squash Vine Borer Moths
- Fusarium Wilt
Harvest/Storage
Watermelons don’t sweeten after they are picked, so harvest time is important. 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.
- ‘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.
Recipes
Wit & Wisdom
What’s in a name? Watermelon is 90% water.
The pumpkin vine never bears watermelons.






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