Planting Tips:In northern or challenging climates, start watermelon seeds indoors about four weeks before your garden soil typically warms. Transplant the seedlings outdoors on a cloudy day into hills with three plants each, spaced about a foot apart. Water well in the weeks following transplanting, and protect young plants from strong winds with row covers or a simple windbreak, such as a wall of wooden shingles set against the prevailing breeze. (Avoid shading them, as watermelons need plenty of sunshine.)

In warmer regions, you can easily direct-seed watermelons right into the garden. Form hills about 2 feet across and 3 inches high, or plant in rows with plants about a foot apart. Sow five seeds per hill, spaced apart and about 1 inch deep, then water thoroughly. When the seedlings emerge, thin to the three strongest plants.

Harvesting Tips: Harvest watermelons when the underside of the fruit turns yellow and the tendril nearest the melon has dried.

Seed Saving Tips: Watermelons are one of the easiest crops for saving seed. As you enjoy a ripe, juicy melon, simply collect the seeds in a bowl. Rinse, drain, and spread them on a plastic plate to dry in a protected spot. Once thoroughly dry, store them in an airtight, rodent- and insect-proof container.

Because watermelons are insect-pollinated, different varieties grown close together will cross. To keep seed pure, grow only one variety per year. Watermelons will not cross with muskmelons, squash, or cucumbers.