Most of the crops we grow at Terra Firma fall into a small group of plant families. Of course there are the Solanums — Tomatoes, Peppers and Potatoes. Cucurbits include Summer Squash, Cucumbers, Melons, Watermelons and Winter Squash. Brassicas or Cole Crops include Broccoli, Cabbage, Kale and Arugula. Beta covers Beets and Spinach. And who can forget the Allium family with Garlic, Onions and Leeks.
But only one plant family does double duty around here as both a cash crop — providing vegetables that we harvest for you — and a cover crop that protects and builds the soil. That would be the Legumes: Beans and Peas.
We grow plenty of leguminous vegetables — Peas in the spring and Green Beans in the summer and fall. But we also grow tons of legumes that are not harvested, but rather grazed by sheep and turned back into the soil. In the winter we grow a cover crop called “Vetch”, which is related to lentils. And in the summer we grow Cow Peas, which are related to black-eyed peas.
We don’t even grow two of the most widely planted leguminous crops in the world. Alfalfa is grown primarily for hay, which we don’t produce. And Dry Beans — the most common legume for most people — don’t grow well here due to the intense summer heat.
Unique among plants, legumes have developed a complex relationship with soil bacteria that allows them to draw nitrogen from the air and store it among their roots. This provides the plants with fertilizer, naturally. It is also why the seeds of legumes, unlike most plants, contain such abundant amounts of protein.
The only real downside to growing legumes is that they are finicky about the weather. The flowers are sensitive to both frost and extreme heat. As a result, there are no leguminous crops that we can harvest during the winter or in the peak of summer.
At any given time, up to a third of our farm is covered in legumes — even the orchards, which we sometimes seed with winter cover crops. Soil loves having legumes planted in it, and the results are immediate and dramatic. Crops that we grow following a leguminous crop always do better than if they had been planted in a field that grew something else. And the soil is loamy and sweet.
Animals love legumes too, both as habitat and food. The enormous Jack Rabbits on our farm love to snack on the newly sprouted bean and pea seeds, sometimes mowing down entire rows. The hawks that help us control rodents are always flying above the fields of cover crop, which are a reliable hiding place for their prey.
Bees and beneficial insects — the good bugs that eat the bad bugs — also love legumes because of their fragrant and abundant flowers. That’s a symbiotic relationship as well: the more bees and other pollinators in a bean or pea field, the more fruit that is produced.
The green beans in your boxes through the fall are not just delicious and nutritious. Because they will all be harvested in the next few weeks, it gives us an opportunity to prepare those fields for next spring’s crop before the onset of winter. And those crops will be happier for having had the beans planted before them.