Cover Crops Boost Soil Power

To Build Soil And Foil Weeds, Sow Fall Cover Crops

Though summer is fading, the still-warm days of fall are an excellent  time to do all sorts of garden chores, from planting trees and shrubs to prepping new beds and lawns. If you’re making new beds, refreshing old ones, harvesting crops and renovating vegetables bed, or planning to install a new lawn, you may find yourself with a goodly expanse of undeveloped soil right about now.

Rather than spending the winter fending off weeds, why not try a cover crop? Cover crops are temporary plantings, useful but doomed to die. They serve several functions, from erosion control and weed suppression to building the tilth and nutritional value of your soil. Cover crops can be tailored for many purposes, and there are all sorts of recipes for cover crops that can help or hinder almost any condition you can think of.

Rolling Over In The Clover

Some blends get pretty fancy, but even a single-ingredient cover crop can work wonders on depleted soils. For instance, nutrient-poor earth can be juiced up fast with a planting of
crimson clover. This handy creeper thrives in clay or sandy soil and takes drought in stride (it’s less vigorous in wet spots, however). Simply by growing, clovers can boost soil nitrogen levels measurably. That’s because the clovers are nitrogen fixers, plants that can draw nitrogen from the air and store it in the plump nodules in their roots. When we turn under or till in red clover next spring, the stored nitrogen will be released into the soil.

Other classic cover crops for lawn areas include a blend of winter rye and vetch. Rye offers strong roots that hold soil in place during winter rains, tall stems that shade out weeds, and plenty of green manure to recycle come spring. Like clover, vetch is a nitrogen fixer that will leave your soil in much better condition once it’s tilled in. This is a pretty crop combo, swaying gently in winter winds, and birds love it for the cover it offers (I often see quail strolling through the rye).

Oats Peas Beans And Barley Grow

Both Austrian field peas or fava beans are terrific soil builders for vegetable beds. Field peas are coarse, mealy legumes used to feed pigs, so don’t try to add these to your dinner menus. They grow best in decent soil with good drainage. Fava beans are also rather coarse plants with broad, flat beans. In Italy, cooked fava beans are served with olive oil and plenty of garlic. Those accustomed to the flavor love it, but if you didn’t acquire it in childhood, you are unlikely to find favas delectable (perhaps I am biased but I think they’re icky). Better to consider them as fodder for soil building, a role they fill brilliantly. Favas grow well in clay soils and are more tolerant than field peas of soggy spots.

Any of these cover crops can be sown now and left to grow all winter. Next spring, you can turn or till them under before they have a chance to complete their growing cycle. The idea is to chop them before they set seed, so you don’t fight volunteer cover crop plants all summer. When you are ready to grow your real crop, whether it’s a lawn, vegetables, or ornamentals, simply turn or till the cover crop under. Wait a week or so for the cover crop to break down, then you can rake out your beds and plant right over it.

Sow Now And Whack Often

In the vegetable garden, you can turn under or till what’s left of your summer crops right in place. Wait a week or so, then sow a cover crop while the ground is still warm. Rake out the soil, then sow your cover crop like grass seed. To be sure you get even coverage, make two passes over each piece of ground (moving in opposite directions each time). Next, rake the seed in a bit (most seed sprouts best when covered to its own depth, usually about 1/4 inch.) Water it well and keep it moist. Most seed will sprout in a week or so, giving you decent coverage in a month. Naturally, growth is slow during the cooler months, but you’ll be impressed with how much happens even in winter. In fact, you may need to weed whack every month or so to keep legume cover crops at the optimum height of about 18 inches. (Otherwise they can turn into a tangled mess.)

When you are ready to turn or till your cover crops in spring, reduce them to stubble with a weed whacker or machete first. When I gardened on a recently reclaimed field, we used an old fashioned scythe to cut the rye and wheat cover crop. This has a long curving blade (just like the grim reaper’s) attached to an even longer and more curving handle called a snathe. It’s quite scenic to watch somebody else use a scythe–the action looks soothing and utterly medieval. However, the repetitive, swinging motion required is harder than it looks. The real trick is to cut the wheat or rye blades so the stalks fall in neat bundles instead of messy tangles. That way, they can be gathered into the classic sheaves to dry. Lacking a scythe, you just whack the tall stems and till or turn under the roots. In a warm year, we can sow any of these winter cover crops through October, but the sooner we get them in the ground, the better they will grow.