Seed Saving Lesson #3: Next Hardest, Cucurbits! by Ruby
In last month’s seed saving lesson, I told you about some plants that you can always and easily save seed from: plants in the sunflower, nightshade and bean families. But not every plant is self-pollinating. Plants that are wind or insect pollinated will cross with members of their same family. Some plants that look differently are actually the same species and can even more readily cross, such as broccoli and cauliflower. Such plants need some sort of isolation from each other in order to ensure that the next generation resembles the current generation. One way to separate plants is by distance and different plants need different isolation distances.. The second method is by timing–only one of that species flowing at the same time within the recommended isolation distance. If distances and timing cannot separate unwanted crossing (in the city it is almost impossible to ensure no one else is growing corn in a 1 mile radius) then the plants must be mechanically contained using cages, bags or other means and then be hand pollinated or insect pollinated by introducing those insects to the cage.
Cucurbits are a wonderful and useful family of plants which includes covers squash, melons, gourds and cucumbers. Isolation distances are not great, but in order to save seed without hand pollination, you must make sure you have only one of each species in your yard. You can have one type of cucumber flowering at a time, one melon, one watermelon, and one each of the following:
Cucurbita pepo all summer squashes (zucchini, yellow squashes, etc.), some pumpkins, pattypan, spaghetti, delicata, and acorn
Cucurbita moschata butternut squash
Cucurbita mixta cushaw, some pumpkins
Cucurbita maxima, kabocha squash, some pumpkins
If that is too hard to keep straight, hand pollination of cucurbita is not difficult and is a great place to start! Male and female plants are easily identified.
The female flowers have a miniature version of the squash below the flower. Tape flowers shut with masking tape the night before they are to open (they will start to turn yellow and bulge out in the center). Tape 3 males for each female. The next morning, gently open the female, making sure no insect pollinators are around. Then rip of the petals of 3 males and swish the pollen grains onto the sticky center of the female. Tape her shut again and mark the stem so that you know this is the fruit with the pure seed.
Full tutorial with pictures here.