Crop fact sheet · Warm season · frost tender
Watermelon
Not in season right now in Houston. Dates below.
Your dates in Houston
| Window | Order seed by | Start indoors | Plant | First harvest |
|---|---|---|---|---|
| Spring 2027 | Jan 11 | Feb 1 | Feb 22 – Mar 29 | from May 13 |
| Fall 2027 | Jul 8 | Jul 29 | Aug 19 – Sep 2 | from Nov 7 |
Worked out from AgriLife planting windows (days before/after average frost) and Houston's average frost dates. "Order seed by" is our own 3-week heads-up, not an AgriLife date.
The numbers
- How to plant
- Sow seed or set transplants 1.25" deep, 54" apart, rows 84" apart.
- Days to harvest
- 80–100 days
- Yield per 10 ft of row
- about 4 fruits (40 fruits per 100 ft of row)
- Keeps producing
- about 4.3 weeks
- Start indoors
- 3 weeks before planting out
- Sun
- Full sun
- Family
- Cucurbitaceae (for rotation)
Water
Watermelons need a lot of water; keep irrigation consistent during fruit set and development (Clemson). Moisten crusted hills after planting.
Feeding
- At planting: 10-10-10 at 4 lb per 1,000 sq ft (60-90 ft of row) in a trench 4 to 6 inches deep, 2 inches from the row; keep seed off the fertilizer.
- Before runners reach 6 inches: Scatter 2 to 3 lb per 60-90 ft of row, 2 to 3 ft from the row, and mix lightly into the soil.
Not sure what your soil needs? Get a soil test first.
Texas heat
AgriLife notes poor pollination causes female flowers to drop or fruit to misshape, a common watermelon problem, and that acidic soil causes blossom drop. Black plastic mulch warms soil for an earlier start. No temperature threshold was given.
Pests to watch
- cucumber beetles
- aphids
- spider mites
- squash bugs
Diseases
- anthracnose
- gummy stem blight
- powdery mildew
- bacterial wilt (spread by cucumber beetles)
What to do about them: pest sheet · what's wrong with my plant?
When it's ready
The tendril nearest the fruit dries and turns brown (most dependable sign), the rind loses its gloss, and the ground spot turns creamy. Thumping is often inaccurate. Cut from the vine with a knife.
Texas tips
- Sow 6 to 8 seeds per hill 1 to 1 1/2 inches deep, thin to 2 plants per hill.
- Starting seed in peat pots 2 to 4 weeks ahead can gain 10 to 12 days; transplant before the second true leaf opens.
- Rows 10 to 12 ft apart if irrigated, 12 to 16 ft if not (Easy Gardening); E-502 table gives 72-96 in.
- Do not plant melons in the same spot more than once every 3 or 4 years.
Varieties that do well in Texas
Allsweet, Black Diamond, Charleston Gray, Crimson Sweet, Jubilee, Royal Jubilee, Mickylee, Sugar Baby (Bush Sugar Baby), Tri-X 313, Tiffany, Gem Dandy, Golden Crown, Yellow Doll