Grow watermelon in full sun and warm, well-drained ground. Watermelon is Citrullus lanatus.
Give it full sun, warm soil that drains, and even water
| Factor | Recommended | Avoid |
|---|---|---|
| Sun | Full sun, at least six hours | Do not site watermelon in deep shade |
| Soil | Warm, fertile ground that drains after rain | Do not leave the roots in a cold, wet pocket |
| Water | Keep the root zone moist, about one to two inches a week; ease off as fruit ripens; water at the soil, not the leaves | Do not let the bed dry out at fruit set, and do not flood the last week |
| Bees | Open flowers so bees can move pollen from male blooms to female flowers | Do not leave a row cover on after bloom starts |
watermelon is a heat crop. Plants stall in cold soil, and a light frost kills the vines. Give it a full day of sun and soil that stays moist after you water, then drains. Water at the base so the leaves stay dry. Once fruit begin to swell, keep moisture even. As the melon nears ripeness, cut the water about in half so the flesh sweetens instead of splitting. [1] [2] The first flowers are almost always male — a plain stem with no swelling. Female flowers have a tiny melon behind the petals. Bees must move pollen; if bees are scarce, pick a male flower in the morning and brush the pollen onto the female stigma. [3] Sow after frost on Planting Watermelon. Cut the fruit only when it is ripe on the vine — see Harvesting Watermelon.
Does watermelon need full sun?
Yes. Give it at least six hours of sun. Deep shade makes weak vines and few fruit.
How often should I water watermelon?
Keep the root zone moist, about one to two inches a week in dry weather. Water at the soil, not over the leaves. Ease off as the fruit ripens so the flesh stays sweet.
Train icebox vines on a trellis
Vines usually ramble on the ground. If space is tight, an icebox type can climb a stout trellis, and you sling each fruit so the stem does not tear.
- Choose a small-fruited type, not a twenty-five-pound picnic melon.
- Set a stout trellis before the vines run.
- Guide the vines up as they lengthen, and sling each swelling fruit.
- Leave two or three fruit per plant if you pinch extras, so the remaining melons can fill.
Do watermelon plants need to climb?
No. Most garden watermelons ramble on the ground. A trellis is optional for a small icebox type, and each fruit needs a sling.
Not a cucumber or a cantaloupe — and not a watermelon peperomia
Cucumber is Cucumis sativus — see How to Grow Cucumber. Cantaloupe is Cucumis melo — see How to Grow Cantaloupe. Squash and pumpkin are Cucurbita — see How to Grow Squash.
Watermelon peperomia is a striped houseplant in Peperomia, not this vine — see How to Grow Peperomia. A watermelon begonia is still a begonia. A shop tag that says watermelon tree is not this rambler. watermelon is Citrullus lanatus, an annual grown from seed. [4]
Is watermelon the same as cantaloupe?
No. Watermelon is Citrullus. Cantaloupe is Cucumis melo, a netted melon.
Is watermelon peperomia a watermelon?
No. Watermelon peperomia is a striped houseplant. Garden watermelon is Citrullus, a frost-tender vine grown for fruit.
If the vines stall in shade or sit in a cold wet pocket, move the next crop to a sunny, draining bed before you sow again.
FAQ
How many melons does one plant set?
About two or three ripe fruit per plant is a fair home-garden crop. Extra small fruit can be pinched so the remaining melons can fill.
Will watermelon come back next year?
Garden watermelon is a frost-tender annual. Frost ends the crop. Sow again after the soil warms.
Why did the first flowers fall off?
The first flowers are usually male, so no fruit forms. Female flowers open later and have a tiny melon behind the bloom. Cold rain or a closed row cover can also stop bees.
What can I plant with watermelon?
Give the vines room first. A low flower such as alyssum at the edge can draw bees. Do not pack cucumber or squash into the same strip; they share beetles and wilt.
Can I grow watermelon in a pot?
A bush or icebox type can crop in a large pot that drains, in full sun, if you keep the mix moist. A picnic melon belongs in the ground.
Is citron or egusi a different plant?
Those names ride on the same watermelon card. They still want full sun and warm soil. They are not a second crop with different care.
What about Black Diamond?
That is a named picnic type of this same plant. It still wants full sun and even water while the fruit fills.
What is eating the seedlings?
Striped or spotted cucumber beetles chew young plants. Cover seedlings until bloom, then uncover so bees can work. Do not spray flowers.
Related guides
Recommended plants
References
- [1] Iowa State Extension -
https://yardandgarden.extension.iastate.edu/how-to/growing-watermelon-home-garden - [2] Utah State University Extension -
https://extension.usu.edu/yardandgarden/research/watermelon-in-the-garden - [3] Clemson Cooperative Extension -
https://hgic.clemson.edu/factsheet/watermelons/ - [4] NC State Extension Gardener -
https://plants.ces.ncsu.edu/plants/citrullus-lanatus/
This note is part of Citrullus Guides.
More first-season notes by plant are gathered in How to Grow Guides.
Updated: Reviewed by Bosquelle Editors