Winter Cover Crops
Cover Crops for Fall Gardens
Cover crops such as fall rye, clover, buckwheat, hairy vetch are another option. These plants act like green manure for the soil, as they decompose they restore organic matter and elevate nutrient levels in the soil. They are sown thickly, so will also out-compete weeds, control erosion from heavy winter rains, and help to prevent the soil compaction over the winter.
Till the plants into the soil in early spring, a few weeks prior to planting, and before the cover crop bolts to seeds.
It is not absolutely essential, but, you may want to conduct a soil test and send some samples to your county extension service or a laboratory for testing. The test results can help determine what adjustments you may need to make to have the garden ready to plant in spring.
An alternative to planting fall cover crops is a thick ground cover / mulch . Leaves are ideal and plentiful . Lay them in a thick layer over the soil and turn them under come spring. To keep the leaves from blowing away , I generally use the bird netting i had in place over my grapes and berries,a fish net will also suffice. Weigh down the corners with rocks or whatever you have available and you should be set for the winter.
Hairy Vetch : Grows up to 2 - 6 feet in height/length most varieties are hardy at subzero temperatures. It is an annual legume and is considered the hardiest of the hardy annual legumes. It matures later than some ground covers and will tolerate poor soil. Generally - I Sow 1/2 pound per 200 square feet, however be sure to follow the seed providers instructions as there are always variables.
Field peas will grows up to 2 or 3 feet tall. They are hardy in temperatures as low as 10 to 20°F.
Crimson Clover Grows about 18 inches high, is hardy to 10° F., matures late and fixes less nitrogen than other clovers. Use as a ground cover in areas where you plan on planting non leaf producing crops in the spring. That is plants such as tomatoes, eggplant, onions - which are not grown and harvested for their leaves. Sow 1/4 pounds per 200 square feet. Crimson clover must be completely removed come early spring, if it is allowed to go to seed - it can rapidly overtake your garden and become an invasive 'weed'.
Winter rye Grows 4 to 5 feet tall; hardy to -30° F. Best grass for cold winter climates: tolerant of low fertility, acidic soils. Sow 2 to 3 pounds per 1,000 square feet. Fall rye,is known to attract beetles, such as adult wire worm beetles to lay eggs. I don't use Fall Rye and don't recommend it .
Annual rye grass Grows 2 to 3 feet high; hardy to -20° F. Fast growing and tolerates flooding. The seeds are inexpensive, and the grass is very hardy. Rye grass can become weedy. Sow 1/2 to 2 pounds per 1,000 square feet.
Barley Grows 2 to 3 feet tall; hardy 0 to 10° F. Fast maturing and tolerant of dry and saline soils: intolerant of acidic soil. Sow 2 to 3 pounds per 1,000 square feet.
Oats Grow 2 to 3 feet tall: hardy to 10 to 20° F. Produces the least organic matter of grasses, but is tolerant of wet soils. Oats usually succumb to winter kill, but the residue is still beneficial to the soil. Sow 2 pounds per 1,000 square feet.
Mixtures are offered by seeds companies such as hairy vetch and annual rye. The vetch fixes nitrogen, while the rye uses leftover nitrogen. Nitrogen from the vetch as it decomposes will cause the rye to break down more quickly and not tie up nitrogen as long.
Cover crops seeds should be sown at least 30 days before the first anticipated Autumn frost date. For cover crops that are only marginally hardy in your area, push back the sowing date to 60 days before the first frost. The more established a cover crop is before the onset of winter the more likely it will be successful.