Oats

Avena spp. Oats are a real workhorse of a cover crop. They are inexpensive to sow, they’re not fussy about their soil, they build generous amounts of carbonaceous biomass, they’re competitive with weeds, they love cool weather but tolerate warm weather, they get along well with legumes like peas and clover in mixes, and they die over the winter (at least in New England—they’re hardy to 15°) so they don’t cause the spring headache that winter rye does.

As if their prowess as a cover crop weren’t enough, the grain may be used as food or feed, and oat straw makes some of the finest, softest mulch you’ll ever have the pleasure to kneel on. Try planting oats in early August and then planting your garlic into the living oats around mid-October—the oats will die over the winter and your garlic beds will be already mulched come spring. And there’s more! Herbalists favor “milky oats” (oat heads harvested when they are still green and the kernels exude a milky substance when squeezed) as a gentle restorative tonic.