Do Watermelons Grow Fast?

Growing Time

• The time frame for watermelons to go from seed to full-grown fruit varies, depending on the variety. Early-season watermelons, such as the Sugar Baby or Yellow Doll, are ready for harvest 70 to 75 days after planting. You can harvest the Crimson Sweet or Sunny's Pride varieties in 80 to 85 days. The latter time frame is also the standard for hybrid watermelons such as the Nova and the Queen of Hearts, reports the University of Illinois Extension.

Planting

• Regardless of variety, the best time to start your watermelon crop is after the danger of frost has passed. Sandy loam soil provides the best growing conditions for watermelons, and you will need "considerable space" for the vines, the University of Illinois Extension notes. Plant seeds 1 inch deep, in hills that are located 6 to 7 feet apart. You must allow 7 to 10 feet between rows; when the seedlings are established, plant them 2 to 5 feet apart. When planting seedless watermelons, plant some seeded varieties with the crop to allow for proper pollination.

Care

• Shallow hoeing is necessary to cultivate your watermelon plants and keep them free of weeds. Clemson Cooperative Extension reports that morning is the best time to water seedlings so that the leaves are dry before dark. It is recommended that you test your soil before applying fertilizer. If you are unable to test the soil, apply a 5-10-10 fertilizer before planting.

Considerations

• You should apply insecticide to your watermelon crop to protect against cucumber beetles and aphids. These bugs are most problematic in the seedling stage, notes Clemson Cooperative Extension. Newly harvested watermelons can be stored, uncut, at room temperature for two to three weeks, the University of Illinois Extension reports. Wash whole watermelons with water before cutting to remove bacteria. Once cut, cover the pieces tightly and put them in the refrigerator. Eat cut watermelon in two to three days.