Growing and Saving the Seed Of Watermelon
Watermelons come in all sizes, from tiny single-serving types only a few inches across to behemoths weighing upwards of 250 pounds! The flesh color is diverse: in addition to the familiar pink-red, watermelons can be orange-fleshed, yellow, and even white.
This crop originated in the Kalahari Desert region of Africa, where its ability to take up water and deposit it into the developing fruits made it an invaluable “living canteen.” First domesticated thousands of years ago in south-central Africa, watermelon was depicted in Egyptian tomb paintings, but may have been grown in India and other Old World locations outside Africa only since about 1000 AD. The crop reached the Americas more recently, carried here by enslaved people from Africa. Appreciated by Native Americans, it was quickly traded throughout the Americas. Today, watermelon is cultivated worldwide.
- Watermelon loves heat. In most climates, watermelon can be direct sown into the garden after frost season ends and soil is warm.
- Soil should be rich and well amended with compost or manure.
- Sow in full sun, preferably where no other melons, squashes or cucumbers have grown for at least three years, to reduce the likelihood of diseases.
- Sow one-half inch deep and 12 inches apart, in rows 6 feet apart. If the soil temperature is right, sprouts appear in just a few days.
- In shorter-summer climates, or to get an earlier harvest, seeds may be started indoors, 3-4 weeks prior to setting-out date.
- Warm conditions yield fast germination; hold at 80 degrees or so. (Use a heating mat if necessary.)
- Once seedlings appear, they need good light—at least half-day direct sun through a south-facing window or good artificial lighting.
- Timing is critical—held in pots for too long the seedlings may become root-bound, which slows the plants down.
- Thin if necessary to stand 2-3 feet apart in the row.
- The vines soon begin to “run” and easily travel 6 feet from the roots as they grow. During this time, control weeds, keep the patch well watered, and watch for watermelon pests.
- Cucumber beetle is possibly the most common pest. Spray with Spinosad as needed.
- Watermelon plants also attract squash bugs. Pyganic or other pyrethrum-based insecticide is a good organic control.
- Watermelons won’t cross with any other member of the squash family, but they will cross with other watermelons.
- Bees carry the pollen up to one-half mile, but adequate purity can be maintained by isolating parent plants by even 1000 feet or so.
- When your watermelon is fully ripe, the seeds are mature as well, although higher viability is obtained by leaving the fruit on a week or two longer.
- Simply extract the mature seeds and dry fully before storage.