Normally when you hear the term “cover up,” it refers to something that is either sinister or political in nature. When it comes to cover up in the garden, it is actually a great thing, because we are talking about cover crops. Cover crops are an important component of any home garden. They have multiple benefits including building the soil, controlling erosion, preventing weed infestation and limiting the spread of certain disease and insects. Cover crops are an extremely environmentally friendly practice that allows the garden to “rest” or leave the garden out of production for a short period of time. While cover crops are traditionally planted in the fall, they can also be used in the spring and summer.
The benefits of cover crops are well known and I personally saw what happens when you do not utilize them. I planted a large summer garden on a new farm tract we purchased several years ago and failed to plant any cover crops that fall. As the summer garden faded and I tilled in the remnants of the crop, my garden looked fresh and well maintained. However, about a week later we had a gully washer of a rainstorm and because of the slight slope I had in my garden area, it looked like a highway system of eroded ruts suddenly appeared the next day. I knew that I made a mistake by not planting some type of cover crop. Even on relatively flat gardens, heavy rains can create havoc on unprotected soils. Every season since then my garden is planted in a fall cover crop, which has become an essential asset to my garden.
When it comes to selecting a cover crop, traditional choices for the fall include wheat, rye, and oats, often mixed with a legume crop such as clover or winter peas. I personally use a mix of winter wheat, oats and crimson clover quite regularly. All of this green material adds valuable nutrition back into the soil once it is tilled in during the spring. The legume crop has the added benefit of providing available nitrogen to the upcoming summer crop. These legume crops fix nitrogen and release it back into the soil once they are tilled in. Summer cover crop selections include seed such as buckwheat, millet or even sunflowers. While on the subject of cover crops, they do not have to be nonedible plants. I have begun planting a mix of cover crops that are both edible and hold the soil. I plant an area of the garden with a broadcast mixture of greens, including mustard, collards, and turnips. I broadcast it out along with fertilizer and allow these to grow in a dense mat on my bare garden soil. I then go in and thin the plants as I harvest to eat accordingly while allowing them to prevent erosion and provide beneficial nutrition later on when they are tilled in.
Cover crops can be established quickly when planted on a well-prepared seedbed. Prepare the bed by removing old vegetable plant material and tilling to a depth of 5-6 inches. Seed or seed mixtures can then be broadcast over the planting area and then lightly dragged or raked in to the soil. It is a good idea to soil test first to determine the pH and fertility needs of your cover crop. Lime and fertilizer can be applied at the time of planting. Take care when planting tiny seeds such as clover as they need exposure to sunlight and should not be covered too deeply. Ideally, they should be just under the soil surface. Seeding rates vary depending on the crop you are planting, but in general 3 pounds of a grass-type cover crop and ¼ pound of clover or peas per 1,000 square feet should get the job done. Legume plants such as clover and peas should be inoculated prior to planting. Inoculation basically means applying an appropriate strain of beneficial bacteria to the seed to assist in breaking down the seed coat. A feed store will help you in the proper selection of the right inoculant. Once cover crops are planted be sure to provide them enough irrigation to germinate and become established. Once established, rainfall will normally keep then thriving and supplemental irrigation is often unnecessary.
Cover crops provide a win-win situation for your garden. They provide benefits at the start by holding the soil and possibly provide an edible harvest as they grow. They also block out weed infestation and other damaging pests. At the end of their cycle, they act as a green manure by providing organic matter and beneficial nutrients to next seasons’ crop. I cannot imagine ever planting a garden again without cover crops.
A version of this article appeared in a November/December print edition of State-by-State Gardening.
Photography courtesy of Bob Westerfield.