Watermelon: Triploid

Growing Tips

Planting

Start in the greenhouse. Allow 28 - 35 days to get plants ready to transplant. Excessive water during germination must be avoided. Water transplant growing medium well and allow excess moisture to drain and moisture to stabilize for 24 - 48 hours. Bring medium temperature to 80 - 95ºF before seeding. Seedcoat adherence to cotyledons may be virtually eliminated by orienting the seed in transplant trays with the pointed end up at a 45º to 90º angle. Plant transplants 6 - 12 feet apart with 36” between plants. 
As a general rule direct field seeding of the pollenizer variety should be done on the same day the triploid seed is planted in the greenhouse. Small-fruited, icebox varieties usually flower earlier than standard watermelon varieties. If icebox varieties are to be used as the pollenizer, then direct seeding should be delayed a week to ten days. The diploid icebox pollenizer variety will frequently set fruit and stop producing male blossoms while the triploid variety is still producing female blossoms.
Growers may make a second planting of a pollenizer 2 - 3 weeks after the initial planting to provide pollen for the late-developing female blossoms on the triploid variety. No consistent differences among any standard and icebox types in effectiveness of pollination have been noted. Icebox varieties used as pollenizers result in high early yields; standard varieties used as pollenizers result in high total yields. 

Management

For successful seedless watermelon production, an adequate bee population is especially important to transfer the pollen from the pollenizer variety to the seedless variety (seedless watermelons do not produce pollen). The pollenizer variety is normally planted in alternate, or every third row to ensure adequate pollen movement by the bees. At least eight visits to an individual flower of the seedless variety are necessary for adequate hormonal stimulation for normal fruit development. Scout fields very 7 days to monitor weed, insect, and disease pressure.

Harvest

Ripeness is indicated by a cream to slight yellowing of the white background color of the part of the melon that rests on the ground. Drying of the stem tendril nearest the attachment point of the watermelon and green color tone of the rind are also indicators of ripeness but these vary with cultivar. Melons should be cut from the vine rather than pulled, twisted, or broken off.

Storage

Store at 50 - 60ºF and at a humidity level of 90 - 95%. This will ensure a long shelf life.