Growing Squash Seed
Written by volunteer Carol Henderson
Last summer, I was initiated into the mysterious rite of hand pollination with the Romanesco zucchini (Cucurbita pepo ‘Costata Romanesco’). Here is the thing; there are many types of squash that manage to cross pollinate with each other and end up sprouting in our compost piles. If we have ever grown any of these creations, we know that we sometimes end up with some funny looking inedible gourds. That is not exactly the kind of seed that the seed garden is trying to distribute. So, in order to control the genetics, and make sure that we were growing a purebred, we spent several evenings and early mornings observing, marking and hand pollinating the flowers.
So here is how it works. When squash plants are in their flowering phase in the middle of summer, they produce both male and female flowers. In the cool of the evening, we observed how many males and how many females we had and determined which ones we felt would be opening the following morning. This requires experience, close observation, and consensus decision making. We marked the male flowers with blue flags and the females with pink flags and then taped the flowers shut with blue painter’s tape so we could control the activity in the morning.
The next morning, we arrived early, just as the flowers were opening, but before the bees were flying. Despite the flags set the night before, it is tricky to relocate the ready flowers against the backdrop of umbrella-like squash leaves. Sitting on upturned buckets, with the utmost of care and gentleness, we un-taped the female flowers, and peeled back the petals of the male flowers and rubbed and shook the pollen from the male flowers inside the center of the female flower. For genetic diversity, we used the pollen from two or three male flowers for each female. The scratchy squash leaves brushed against our arms as we were crouched doing this important work. After the pollination process was complete, we again taped the female flower shut with blue tape to prevent any bees from flying into the flower and bringing with it pollen from some unknown source. For me, this was the hardest part. It was awkward to do, important not to jostle the flower too much, and it was imperative to create a solid seal. After closing the seal, we marked the whole plant to identify that we had, in fact, intervened in the pollination process. This careful process was repeated for many mornings with us taking turns—the more experienced seed midwives, and me, the initiate.
The waiting began and each week, we would look and see which pollinated flowers were forming fruit. Not every procedure takes, and after all of that work, we were happy to have a high success rate and only a few withered flowers to remind us of the unpredictability of life and death. Twenty-one very plump ripe zucchini produced four jars of cleaned seed that we had hoped would last the Seed Library for a few years. In the time of pandemic, the seed has been generously distributed across Sonoma County and hopefully being grown in many gardens. In order to replenish our stock, this summer I will get another chance to try my hand at the mysteries of seed midwifery. I think I’ll brush up on my taping techniques first.