Melon Seed Saving
If you can grow melon for the fruit, you can grow it for seed, too. In order to save pure seed, you must prevent bees from leaving traces of pollen from other varieties, thereby contaminating the seed stock. There are two basic ways for the home gardener to exclude foreign pollen: isolation and hand pollination. Isolating single varieties of a species by distance is the easiest way, the one I recommend for starters. You’ll have to limit yourself to one melon and one watermelon that you value and know to be heirlooms rather than F1 hybrids. Since they don’t cross with each other, you can grow them in the same garden. You must ensure, however, that they are at least a half mile from other melon varieties, with which they could cross-pollinate.
There’s no need to sacrifice the fruit for the seed. When you’re ready to eat the melons, cut them open. It’s easy to scoop the seeds from the center of a muskmelon or honeydew. But because watermelon seeds are scattered throughout the flesh, they present a bit of a challenge. Put the seeds in a colander, discard attached flesh, and rinse them, gently rubbing to remove stickiness and tissue. Shake off the water, blot extra moisture from the bottom the colander with a paper towel, and turn the seeds out onto sturdy, absorbent paper plates. Dry the seeds at room temperature for two or three weeks, occasionally turning them over on the plate plate, until they can be cracked or easily broken in two.
Heat and humidity will cause the dried seeds to lose their vigor, so store them in paper packets in airtight containers, in a cool, dark, dry place such as a refrigerator. Seeds that are well cured and stored remain viable for at least five years, but don’t let them languish in your refrigerator. If you share your seeds with other dedicated gardeners, you’ll be doing your part to ensure that heirloom melons do not vanish from the earth.