STRIKING GOLD with GREEN MANURE

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Improve your soil and increase vegetable
yields with easy-to-grow cover crops.

by Kris Wetherbee

Whether you garden in raised beds, a small backyard or on acres of land, cover crops can provide a wealth of benefits to the garden. For one, they often grow fast and develop in thick stands. Plus, they provide nutrients to turn a cover crop hack into the garden while the plant is still green and it's called "green manure."

If you have a weed problem, fast-growing cover crops like buckwheat, red clover or Austrian peas can outcompete and smother unwanted invaders. Even closely planted sunflowers, with their allelopathic tendencies, are a good weed-suppressing crop. While a sunflower grows, it temporarily inhibits nitrogen-fixing bacteria in the soil ...bad news for the germination and growth of any plant needing nitrogen. And few plants need nitrogen more to germinate and grow than do the weed grasses.

Is your garden crawling with pest insects? Cover crops are a boon to beneficial life - providing food and shelter for both soil-dwelling creatures and aboveground insects that pollinate and help control garden pests. Countless beneficial insects thrive on the pollen or nectar of cover crops in bloom. (Pest insects, conversely, feast not ran pollen but on plants, choosing their targets by the gaseous odors they emit. In my experience, cover crops have far less trouble with pest insects than do vegetable crops.)

If you're looking to lure welcome guests to your garden, look no further: alfalfa attracts a host of parasitic wasps, lady beetles, damsel bugs, big-eyed bugs and assassin bugs. White clover attracts tachinid flies, ground beetles and parasitic wasps that prey on aphids, scales, caterpillars and whiteflies. Most grains attract lady beetles. Clovers and vetches attract minute pirate bugs. Fava beans attract predatory and parasitic wasps, as does buckwheat, which has the added benefit of luring syrphid flies (also called hover flies) and bumblebees.

Cover crops are good for the environment, too. Established legumes or fall sown, grains and grasses that quickly cover the ground protect the most fertile part of your soil from erosion caused by assailing winds and pounding storms. Likewise, grasses, grains and brassicas that grow quickly in the fall help capture easily leached nutrients like nitrogen and calcium before they wash away with winter rains. When you turn these crops under in spring, the needed nutrients are released back into the soil.