Cover Crops: The Unsung Heroes of the Garden
May 7, 2026
min read
Farmer Sam dipped a coffee mug into a bag of rock powders, scooping out three mugfuls and sprinkling them on the bed before him. “I often measure things in coffee mugs. I always have one on me, so it’s an easy way to keep track of things.” While his methods seemed curious, it was less interesting than the task at hand: planting cover crops in a bed that previously grew potatoes.
After a swarm of excited elementary school students fork through a 50’ x 50’ potato plot, the block needs a little support to restore balance, which is where cover crops come in.
Cover crops are plants we grow not to harvest, but to feed and protect the soil. Their living roots support the tiny organisms underground that keep soil healthy and the above ground biomass will eventually be incorporated into the soil once the crop is terminated, breaking down into the bed, feeding microbes and adding organic matter back into the soil. We cannot simply take and take from the garden without giving something back. Adding compost, manure, or granulated fertilizers to a garden bed can be a quicker fix, but growing cover crops is perhaps the healthiest way for us to support the complex soil ecology and regenerate the ecosystem in our wake.
The primary drawback to cover crops, however, is the time and logistical investment. Cover crops can tie up a bed for up to an entire growing season and if not terminated properly can create a massive weed problem in the garden. But the long term investment in soil life, improved texture, added nutrients, reduced weed pressure, and important food sources for indigenous pollinators is well worth the trade off.
On our farm, we often mow the cover crop, cover the bed with a silage tarp for two to four weeks and then plant into the residue left behind. That residue is especially good for transplants, keeping weed pressure down while the soil continues to digest all that plant matter. At Glen Brook, Farmer Sam especially loves a spring terminated winter rye for brassica transplants and we fall oats preceding garlic, which are terminated immediately prior to planting and act as a delicious mulch through the winter and into the spring.
Different vegetable crops have different fertility demands as well as create or break certain pest cycles. Quick crops like radishes are light feeders, while dark leafy greens like spinach need more nutrients. By paying attention to what each bed has grown, and by using cover crops and crop rotation we strive to continually improve the garden’s health, increasing the percentage of soil organic matter and supporting a diverse and complex ecosystem.
