Fruit / Warm season
Watermelon
A summer-long project that fits a yard, not a balcony
Plant out byMay 18zone 6
- Family
- Gourd (Cucurbitaceae)
- Sun
- Full sun (8+ h)
- Difficulty
- Fussy
- Days to harvest
- 70-100 days
- Spacing
- 48 in apart, rows 72 in
- Pot size
- Beds only
- Frost
- Tender
- Start
- Either
- Water
When to plant
Showing .
Averages for a typical garden in the region. Your local frost dates may differ by 2-3 weeks, check a local source.Too late this year (try fall)
In zone 6, start seeds indoors Mar 30 to Apr 6; plant out Apr 27 to May 18. Average last frost Apr 20, first fall frost Oct 20.
Units
The thump test gets all the attention, but it is the hardest sign to read. The clearer clues sit on the plant. The curly tendril closest to the fruit turns brown and dry. The skin loses its shine. Last, the spot where the melon rests on the ground goes from white to cream or yellow. Check all three before you cut the stem. A ripe one also feels heavy for its size.
Room is the first hurdle. Full-size vines need around 20 square feet each and wander well past a 4×8 bed. Small icebox kinds like 'Sugar Baby' are easier to fit, and a bush type can limp along in a large tub, but this is a ground crop. Give it the sunniest, warmest patch you have, with eight hours of sun as the target. Cucumber beetles, squash bugs and aphids do the most harm while plants are young, so cover seedlings until flowers open.
Plant out about two weeks after your last frost, once soil 4 inches down is 65 degrees F or warmer. Start seeds indoors only 2 to 3 weeks ahead, since older seedlings transplant badly. Black plastic mulch speeds things up in cooler areas. From there it is a long, hot run of 70 to 100 days depending on variety. On an August afternoon, cutting the first one open on the back steps with the kids is the reward for giving up all that space.
Things to consider
- Water deeply while vines grow and fruit swells, then ease off in the last week or two. Too much water at the end can dilute the flavor. Keep it steady until then, since big swings can crack the rind.
- Set young fruit on a board, a tile or a bed of straw. It keeps the rind off wet soil and makes the ground spot easier to check. Lift gently, because young melons snap off the vine easily.
- Seedless watermelon will not set fruit alone. Plant a seeded variety within about 10 feet so bees can carry its pollen across. Some seedless seed packets include a few seeded seeds for this reason.
Good neighbours
Keep apart
Pests to watch for
Cucumber beetlesSquash bugsAphids
Questions about growing watermelon
Can I grow watermelon in a raised bed?
A raised bed works if the vines can spill over the sides onto a path or lawn. The soil warms faster in spring, which melons like. Pick a small variety and expect the vine to cover far more ground than the bed. Mulch the path where the vines land so fruit does not sit in mud.
Why did my small watermelons turn yellow and fall off?
Young fruit that shrivels usually was not pollinated well. Cool weather, few bees or crowded vines can all cause it. The plant also drops extras it cannot carry, so a few losses are normal. On a street with few bees, a soft brush in the morning can help.
How long does a watermelon take from flower to ripe?
About 35 days from fruit set, according to Clemson's extension guide. Writing the date on a plant tag when you spot a new melon tells you when to start checking. Hot weather speeds it up and a cool spell slows it, so treat the date as a reminder.
Save this crop
Pin it to a garden board so it is there when planting time comes round.
Similar crops
Sources
General guidance for home gardens. Frost dates are averages for a zone or region; check a local source (in the US your county extension office) for local timing.