I didn’t do so well at planting a winter vegetable garden this year (I am terrible at planning for winter in the height of summer, which is, unfortunately, when you need to do your planting for winter harvesting). Other than some quick-growing salad greens that I managed to sneak in at the beginning of September, the holes left by my tomatoes, beets, kale and herbs might have gone unfilled all winter, if it weren’t for cover crops.
A cover crop, also known as green manure or living mulch, does double – make that triple – duty in the winter garden.
First, it protects your soil from harsh winter weather, preventing erosion, compaction and nutrient leaching. It also smothers weeds.
Second, it fixes nitrogen in the soil. There’s a whole scientific explanation behind the “fixing” of nitrogen, but all you really need to know is that cover crops, many of which are legumes, add nitrogen back into your soil, prepping it for spring planting. It’s a great service to soil that has been depleted by hungry feeders like tomatoes.
Finally, cover crops produce armloads of organic matter, improving soil structure when the crop is dug under in the spring. If you prefer not to till your soil, the cut greens make a great boost for the compost pile. Yay!
So what do you do in the spring? Watch for flowers: they’re the indicator that it’s time to either dig under your crop or cut it down, leaving the roots in the ground and using the greens for your compost. If you dig under your crop, let the soil rest for three weeks before planting. Enjoy improved soil fertility and structure.
Popular winter cover crops include red clover, hairy vetch, fall rye, fava bean, alfalfa and Austrian winter pea.
I like using a blend of fall rye and crimson clover.
Fall rye is super winter hardy cereal crop that prevents soil erosion and smothers weeds. Turned under in spring, it decomposes and improves soil. According to West Coast Seeds, fall rye gives off a chemical that inhibits the germination of weed seeds. Planted twice in a row, it can choke out several tough weed species for good.
Crimson clover builds nitrogen in the soil and tills under easily. Pollinators – especially bees – love it. Plant before early October.