In a previous guest post for UC Food Observer, I quoted my FarmLab message to third graders: “Crops’ are what we grow for people, and ‘cover crops’ are what we grow for the soil.” As with all simple messages, something must be left out for brevity. Missing from that statement is another important service that cover crops deliver, especially in the summer: bee forage.
Summer would seem like a great time to be a bee. Many plants are in full bloom. But a pollinator in my neighborhood might find it tough going right now. While lemons bloom nearly year round in coastal Ventura County, they don’t have a lot of blooms during the peak of summer. Avocados have already had their blossom for the year, and hundreds of acres of nearby strawberry fields have been turned under in preparation for next year’s crop. Make a circle of one mile radius from the center of Petty Ranch, and you will find that there just aren’t a lot of flowers in July and August. But there are flowering cover crops.
Our summer cover crop program looks quite different from our winter program. For starters, it is much smaller. We aim to have all 50 acres covered in the winter. We want to cover as much ground and convert as much rainfall to soil organic matter as we can.
In the summer, the acreage is only about an acre. With no summer rain to capture, maintaining cover on the whole farm would increase our water consumption too much. We can only make soil building a priority when we get free water from the sky. Lemons and avocados need their summer water, and we can’t have a cover crop competing with them.
Our figs tolerate a little friendly competition just fine. In fact, the competition for soil moisture may tame their vigor a bit during the warm summer months and help sweeten the fruit. Given the heavy soil in that part of the orchard, we keep our soil building efforts going year round.
Deep rooted daikon radishes drill deeper into the subsoil in search of water, helping to open it for our trees, and banking organic matter for the future. But they also bloom profusely, providing a much needed buffet for our hives. Daikon is becoming one of our “go-to” summer cover crops. Nutrient scavenging buckwheat is also a summer time stand-by, and its abundant white flowers make great forage as well. Sunflowers, Sudangrass, and occasionally pumpkins work the soil as well.
It isn’t only Farm Lab’s hives that benefit. In addition to our resident honeybees, wild bumblebees are frequent visitors to the radish flowers. I rarely see them on the farm except when the daikon is in bloom, so they must be traveling some distance for a favorite food item. I regularly spot small native bees, at least two different species. I’m sure a more learned eye could easily identify more.
Our first halting steps into summer cover crops were motivated entirely by the desire to enrich our soil. It has been a pleasure to learn that it has not only done that, but that these efforts enrich other aspects of our farm as well, from the pollination of our lemons and avocados, to the education of elementary students.