Seed Saving: How to Save Squash Seeds

Commercial seed producers run machines through entire fields harvesting the seed in the field. This method of harvesting automatically selects for plants that have bigger seed cavities and more seeds but thinner flesh. It also auto­matically selects for smaller seeds; the fruits with more but smaller seeds will contribute a larger fraction of the plants in the next generation. The original ‘Sweet Meat’, with its thick, very dry flesh, tiny seed cavity, and huge seeds, has only about 250–350 seeds in a 20-pound fruit (as does my line, ‘Sweet Meat–Oregon Homestead’). Is it any surprise that the commercial industry ended up with a variety with a seed cavity two or three times as big, with much thinner fruit and smaller seeds? That is what they were selecting for.

Seed savers sometimes say they only want to maintain preexisting varieties such as heirlooms, not to do plant breeding or create anything new. However, competent seed saving requires plant breeding. In addition, some varieties are always lost through time, or become unworkable as the plant diseases or human needs and standards evolve. Our ancestors were creators of culture, not just passive transmitters. They created new songs and new learning and new technology as well as transmitted the old traditions. They both created and transmit­ted crop varieties. We should too.

The essence of selection is to save seeds from the best. Obviously, we do not want to save seed from the worst plant we have. If some or all of its being worst is heritable, we would be selecting for a variety that would be inferior to what we started with. We want, if possible, to be improving a vari­ety. So we want to choose our seed fruits from our best plants. But what is “best”? Clearly, the biggest fruit in the patch isn’t best if it is the only fruit the plant produced. We want plants that are generally productive and that produce fruit of the right size that is true to type. Furthermore, half the genes come from the pollen parent, the “father” squash plant. We would like that plant to be best too. But that is just a start.

Many of the characteristics we care about with squash and pumpkins aren’t apparent until the end of the season or even until after fruits are harvested and opened and tasted. So I usually do several hand-pollinations of several fruits when I want to save seed, recording both the female and male parent on the piece of surveyor’s tape I use to mark each hand-pollination. (Again, as stated before, I number all the plants in the patch with a number based upon row number and position in the row.) Then I evaluate all the plants toward the end of the season, noticing and noting any that weren’t as productive or weren’t what they should be. I also notice any significant differences in powdery mildew resistance (which we always have here late in the season), or anything else notewor­thy. I record the plant number with a permanent marker near the stem of each fruit before I harvest. Then I open and taste fruits from relevant plants (those representing plants for which I have hand-pollinations) before making the final seed-saving decision, to make sure they have the appropriate thickness of flesh, flesh quality, and flavor. So a good parent plant must produce a good number of fruits of the right size and shape and type, be vigorous, and be relatively disease free for the vari­ety, and its fruit must have all the culinary char­acteristics it should have. I usually make several hand-pollinations using different plants, then save seed only from the fruits that had the good female as well as male parents.