Spaghetti squash (Cucurbita pepo) produces large seeds that store for up to six years, provided they're properly collected and prepared. Named for its cooked flesh, which resembles spaghetti, spaghetti squash is also called spaghetti gourd, vegetable spaghetti, Manchurian squash and squaghetti. The fruits are smooth-skinned, about 10 inches long, 5 inches in diameter and weigh about 2 pounds.
Spaghetti squash fruits are ready for harvest about 70 to 80 days after sowing. Only seeds from ripe fruit are likely to sprout when sown later. Harvest spaghetti squash when the vine stem withers and the fruit skin is tough.
If you aren't sure whether a spaghetti squash fruit is ripe, push a thumbnail into the skin. If the fruit is ready for harvesting, your nail won't pierce the skin.
Seed from spaghetti squash fruits must be separated from the pulp and soaked in water. Healthy seeds sink to the bottom in a few days.
Cut a spaghetti squash in half lengthways with a sharp knife.
Scoop the seeds from the center with a spoon.
Put the seeds in a jar or bucket with an equal amount of water.
Stir the seed and water mixture once a day for two to four days. A mold may form, but this is harmless.
When some seeds sink to the bottom and some float, pour off the water, pulp, floating seeds and mold.
Spread the remaining seeds on a paper towel or screen to dry.
Drying and freezing spaghetti squash seeds helps keep them fresh and free of pests and diseases. When the seeds are completely dry, place them in paper envelopes or glass jars. Write the name of the seed type and the date on the envelopes or jar labels, and put them in a freezer. After two days, transfer the seeds in their storage containers to a refrigerator. Plant the seeds within three years.