Updated: May 2019
Today I want to write a bit about what Carol Deppe, in her book The Resilient Gardener, calls “the ultimate act of gardening resilience:” Saving our own garden seeds. In this case, how to save winter squash seed. If you haven’t checked her book out, I highly recommend it. It’s easy to gather reading her work that she is a thoughtful, present and active observer of nature and how we and our gardens fit into the bigger picture. She definitely practices what she preaches. That said, I’m just an amateur, so perhaps this post will be a good starting point.
Some Background Info
There are are 3 major squash species grown in North America: Cucurbita maxima, C. pepo, and C. Moschata. The buttercup squash that we grew this summer is a member of the maxima group, and an important thing to know about any squash in this group is that they require at least one month of storage indoors to cure properly. According to Ms. Deppe, some varieties only get sweeter as they age six months or more. That also means they are good keepers. Compare this to the pepo group, the one I know best are the Delicata, which only need to cure for two weeks and are best eaten before Christmas (so I’ve read). We started eating our Buttercups in mid December, before that we were eating a variety called Winter Luxury, a pepo. So far, the Buttercup have been consistently sweeter and a bit creamier than the Winter Luxury. Next year I am thinking about growing only Buttercup. Growing out a larger number of a single type will give me a better chance (if I do a good job of selection) of obtaining high quality seed. I’m also intending to direct seed instead of starting transplants in the greenhouse. Ms. Deppe goes into a good reason for doing this, but for now I will just say I want to do it because she said so, and that’s good enough to give it a try.
We store our squash in an insulated but unheated shop space inside cardboard boxes. It would probably be better to store them in a single layer, but we don’t have space for that. They are storing reasonably well there. We’ve had some moldy stuff on some fruits, so the humidity may be a bit high (are winters are wet enough that mold is growing on some of our patio furniture). So another lesson learned is to check your stock frequently, eating or composting anything that is going south. A good preventative measure is to only long-term-store nice clean fruits without any damage. The general guidelines for storing squash are to put them in a cool (50-55 degrees) and relatively moist place(50-70 percent humidity). Our shop is considerably cooler, in the 30s and 40s most days, and probably in the high range of that humidity. The squash seem to be doing reasonably well in there.
Now back to the seeds. I use stainless steel screens from Horizon Herbs and a mixing bowl to wash and clean the seeds. I usually start with the mixing bowl, but it probably doesn’t matter. Running water through the pulpy seed and rubbing begins to loosen and separate the seeds from the pulp. Once the bowl is pretty full I shut off the water and continue to work the seeds free while submerged. It’s best not to let them soak too long! Then I pour off the seeds and water into the screen where they get rubbed and more water through them. You could use a standard kitchen strainer, but I found that the larger holes on the seed screen let more pulp through (go figure). Once they are clean I spread them out as much as possible on the screen, or if there are a lot of seeds transfer some to a second screen, and place them near our wood stove to dry down. I fan would really speed things up but I just haven’t felt like going there. Ms. Deppe recommends drying the seeds down in a dehydrator for the best long term storage, but again I haven’t gone there. Another good tidbit I learned from the book is to test the dryness by shelling a couple seeds and checking to make sure the “meat” is actually dry before putting the seeds away till planting time. If you don’t really dry the seeds down, ie with heat and air flow, she advises putting them into a breathable vessel, like a bag or envelope. Once the seeds are dry and stashed in the appropriate container, move them to a cool and dry location until planting time.
I will post an update when the soil warms up and we start popping these babies in the ground.
Happy seed saving,
ps. for more info on seed saving and breeding, check out: