The Birds and the Bees
At this abundant time of year, the garden is alive with insect and bird movement as well as the rapid growth and maturity of the plants. Bees travel from flower to flower, birds swoop in and out, and leaves and vines continue to reach for the sky. All of this activity is leading to the work of the plants and the mission of our garden, which is to produce seed. It is important to remember that it all starts with the magic of pollination. The Seed Garden is surrounded on all four sides with a pollinator border that is filled with many California natives and other flowering plants that are grown to encourage our winged friends to visit. To read more about some of the plants that grow in the border read this article.
Plants can either self-pollinate or need to be cross-pollinated. With self-pollinating plants, the pollen from the flower’s stamen lands on the stigma and fertilizes itself, thus producing fruit and seeds. An example of a self-pollinating plant is the tomato. With cross-pollinated plants, the pollen moves between the flowers or between the plants of the same species. This can be done with either pollinator insects or by the wind. In some places bats and birds can also act as pollinator agents. Examples of cross-pollinated plants include squash and kale.
We grow heirloom varieties and allow our plants to be openly pollinated, which means we allow natural pollination through self, insects and wind to occur. In other words, we are not manipulating the plant genetics in a lab and as such, we are encouraging our plants to produce seed that will grow “true-to-type” meaning that the seed we save will produce offspring with the characteristics of the parent plant.
With this in mind we have to be intentional about how far apart we grow certain crops that are different varies but in the same species, for example Mayan Jaguar lettuce and Little Gem lettuce need to be at least 10 feet apart to avoid unwanted crossing. Isolation distances vary from 10 feet to several miles depending on the species of the crop. When saving seeds, it is important to know the species of the varieties you are growing. If cross pollination happens between two varieties of the same species the seeds produced will have genetic material from both parents and the plants grown from these seeds will display characteristics of both parents and will not be the same plant we thought we were saving seeds from. It is for this reason that we hand pollinate certain squash we grow to make sure the seed we distribute is the variety we intend. For more information about how we hand pollinate the squash read this article.
Another way to prevent cross-pollination of crops of the same species is to stagger the planting times so that the flowering and pollination occurs at different times of the year. In other words, we try to plan so that one variety will already be making seed by the time the other variety is flowering. With fluctuations in the weather patterns, this can sometimes be tricky as flowers may bloom earlier or later “than usual.” That happened this year and we had to sacrifice a crop of kale to make sure the broccoli seed would not been cross-pollinated.
As you watch insects traveling around your garden at this time of year, ask them where they have been and be thankful for all of the important work our little friends are accomplishing so that we may be able to enjoy the fruits of our labor and to save our seeds for another year.