Vegetable Gardening (114 page)

Berseem clover,
Trifolium alexandrinum,
grows 1 to 2 feet high and is easy to mow and till under. It's hardy to 20 degrees. Sow 2 pounds of seed per 1,000 square feet. Crimson clover,
T. incarnatum,
is closely related, grows 18 inches high, and is hardy to 10 degrees. It has pretty red flowers that attract bees.

Buckwheat,
Fagopyrum esculentum,
is fast growing, reaching 3 to 4 feet tall in about 40 days from seeding. It provides lots of organic matter, smothers weeds with its large leaves by shading them out, and exudes chemicals to prevent weeds from germinating. It breaks down quickly in the soil after tilling. Sow 3 pounds of seed per 1,000 square feet. Buckwheat doesn't fix nitrogen and is frost sensitive, so grow it in summer when the temperatures are warm.

Fava beans,
Vicia faba,
grow 3 to 8 feet high and are hardy to 15 degrees. Bell beans are a shorter (3 feet) relative. Edible varieties include ‘Sweet Loraine' and ‘Windsor'. Sow 2 to 5 pounds of seed per 1,000 square feet.

Field peas,
Pisum arvense
or
P. sativus,
come in several varieties that range in height from 6 inches to 5 feet high. They're hardy to 10 to 20 degrees. Sow 2 to 4 pounds of seed per 1,000 square feet.

Hairy vetch,
Vicia villosa,
is the hardiest annual legume (-15 degrees) and grows about 2 feet high. Sow 1 to 2 pounds of seed per 1,000 square feet.

Winter rye,
Secale cereale,
is a very hardy grass (-30 degrees) that grows 4 to 5 feet high. It's the best grass for cold areas with poor, acidic soils and produces lots of organic matter. Sow 2 to 3 pounds of seed per 1,000 square feet.

If you want a wide selection of cover crops plus a lot of helpful information, check out the Peaceful Valley Farm Supply Web site at
www.groworganic.com
(see the appendix for address information).

Planting cover crops

The best time to plant cover crops is late summer to early fall. What happens next depends on the climate where you live:

In mild-winter areas,
the plants will grow throughout winter and can be turned into the soil in spring.

In cold-winter climates,
plant hardy types that will grow for a while in fall, go dormant, and then grow again in spring before eventually dying. Some less hardy types, such as annual ryegrass, will die back in winter and be easier to till under in spring. You can work them into the ground in late spring or early summer and plant vegetables soon after.

An early spring planting of cover crops also works in cold-winter climates, but you won't be able to work the plants in until later in the summer.

Because beds planted with cover crops won't be available for planting vegetables until you turn them under, you have to plan ahead to use your garden efficiently. If you're short on space, consider alternating vegetables and cover crops so that each bed gets a cover crop every 2 or 3 years instead of each year.

If you plant cover crops in fall after your vegetables are done, you won't miss a beat and can plant vegetables again in spring. If you plant cover crops during the spring or summer, you'll have to sacrifice some space in your veggie garden. I'd opt for this route only if your soil is very poor and you need to build it up while growing vegetables at the same time. Just rotate where you plant the cover crops in your garden, and after a few years, your whole garden will get a cover cropping.

Plant cover crops by broadcasting seed (Chapter 13 has more info about this technique). To make sure the proper bacteria are present for nitrogen fixing in legume cover crops, use an inoculate. Most suppliers sell an inoculate that you mix with the seed. Till the soil, sow the seeds, and lightly cover the seeds with soil. If the weather is dry, water the seedbed to get the plants off to an early start and then keep the soil moist until it rains.

If you grow cover crops up to planting time (spring or fall) in your garden, the best time to work the cover crops into the ground is just before they start to bloom. With taller types, you may have to cut or mow the plants down before turning or tilling them in. After you work them in, wait about 2 weeks before planting vegetables.