There are five species of squashes. If you select one variety of each species, then you can grow them and never
experience any hybrids. Establishing
volunteer colonies of squashes
should be
sustainable. Make sure you have no other squashes growing within a 1/2 mile radius.
Squash: within the genus of 'Cucurbita' there are 5 species of squash that are commonly used for food.
Gardening multiple varieties of a species of squash near each other will normally result in useless hybrid seeds. If you grow squashes [squishes?] of different species next to each other and save your
seed, then those seed should remain true for the next year's crop.
With that in mind a quick review of squash species is in order.
Cucurbita argyrosperma [mixta] - cushaw pumpkin, Japanese
pie pumpkin, or pipian
Cucurbita ficifolia - Siam pumpkin, Thai marrow, Thin Vermicelli pumpkin, Asian pumpkin, fig-leaf gourd, pie melon, or
Malabar squash
Cucurbita maxima - Arikara squash, banana squash, Boston marrow, buttercup squash, hubbard squash,
Jarrahdale pumpkin, Kabocha, Lakota squash, Turk's / French turban, and some varieties of gigantic pumpkins.
Cucurbita moschata - Butternut squash, Calabaza pumpkin, Dickinson field /Libbys pumpkin,
Giromon, Kentucky field pumpkin, Long Island cheese pumpkin, Long of Naples squash, Neck pumpkin,
Seminole pumpkin, and Tromboncino.
Cucurbita pepo - Acorn squash, Cocozzelle, Crookneck, Delicata squash, Dodi marrow, Gem squash,
Heart of gold squash, Pattypan squash, Some types of Pumpkin, Scallop, Spaghetti squash, Straightneck,
Sweet dumpling squash, Yellow crookneck squash, Yellow summer squash, and Zucchini.
For sustainable
gardening with the intent of saving seed, you can safely grow one variety of each species of squash. In this manner most of your seed should be true to species and provide you with the next year's seed.