There are a few varieties of squash my family cannot do without. We require spaghetti squash with sage and browned butter in the summer, pumpkin for pies in the fall and if there was no butternut squash with bacon crumble for Thanksgiving, there would be a riot at the dinner table. And don’t forget Grandma’s zucchini bread. So, how do I save seeds without the squash crossing until they are all one inedible warty squash mutant?

Lazy Gardener Methods

It’s easier than you might think even though the fat, black Carpenter bees in my garden love squash flowers and will happily mix pollen from one flower into another all day long. There are four main species of edible squash. The ‘Rugosa’ Butternut squash I favor is from the species Cucurbita moschata. To keep it from crossing all I need to do is keep it away from other squash I want to grow that are in the same species. For us that means the ‘Tromboncino’ that we often use in place of a true zucchini needs to be as far away as possible from the “Rugosa’ patch.

I can grow the spaghetti squash that we like right next to the “Rugosa’ because the spaghetti squash is a Cucurbita pepo. But it can’t be near the pie pumpkins because they are also C. pepo. As long as you know which species of squash you are growing, you can separate them enough to prevent most cross-pollination. I do this by growing one variety of each species in front of the house and one behind. You could plant on either side of a hedge or other windbreak and do a pretty good job of keeping your variety breeding true. Or you can separate the plants with time. If I put in my spaghetti squash very early from transplants, or under a row cover, or both, and I don’t plant out my pumpkins until the spaghetti squash have each set a few fruits, then I can grow the pumpkins right beside my developing squash and pinch off any extra flowers that try to develop on the spaghetti squash plants once the pumpkins start to flower.

Precision Gardener Methods

A Mother of a Hubbard

If you are determined to maintain a squash variety with maximum purity, you have several options. You could alternate years of growing for varieties that are in the same species. Year One I would grow ‘Rugosa’ squash and then can or freeze what we would need during Year Two when I would be growing the ‘Tromboncino.’ But even then, a bee from a neighbors garden could stop by and ruin things inadvertently. You could alternate days, or even weeks, when you “cage” one of the varieties or the other. Large sheets of row cover are best for this with squash and you would have to be sure you tucked in the edges and laid a board or something heavy over them to make sure they didn’t blow off exposing both varieties to insects at the same time.

Or you could hand-pollinate, which sounds fussier than it actually is. You have to keep an eye on your squash blossoms as they develop and know which are male and which are female. And you will need to tape the female flowers that you want to hand-pollinate shut to prevent them from opening on their own, ideally the night before they would have opened. You pollinate that flower with pollen you know came from a male flower of that same variety and then you tape that flower shut again and tag the baby squash behind it so you can save the seeds only from the tagged squash. If I’m making this sound complicated, check the videos or instructions available on the Internet. This is the best method if you are preserving a rare variety, a family heirloom, an unusual squash where you won’t be able to easily get more seeds, or if you are saving seeds for trading and sharing.

If you have favorite seeds saving methods for squash, we would love to hear them. Please share in the Comments.