How to use cover crops in the garden

The use of cover crops in a home vegetable garden is a resource not used enough by local gardeners. There simply are too many benefits of cover crops to not plant them in some format in your garden areas.

Just a few benefits of covers crops are in the areas of building the soil, helping control soil erosion and even limiting the start and spread of certain disease and insect issues in the soil. In regards to cover crops, you have options for cool season cover crops as well as summer cover crops depending on the situation.

Today, I will be sharing information from a UGA publication by Bob Westerfield, UGA Extension Horticulturist, and Carmen Westerfield, USDA District Conservationist.

For starters, there can be many rewards for using a cover crop in your vegetable garden. In our area, many of our gardeners will plant summer gardens only so cool season cover crops will be the main consideration.

After gardening season, many people will leave a garden spot bare. If you plant a cover crop on that bare soil, it can assist in germination reduction of unwanted weeds and can reduce soil erosion. Crop crops can even add nutrition to your garden area too when turned under and allowed to decompose in the soil. The organic matter in your garden spot can increase too with the use of cover crops. I will add that cover crops can aid in the increase of beneficial insects including pollinators.

Some gardeners will plant cover crops between garden rows to reduce weed germination in those areas and to hold soil. Using cover crops in combination with crop rotation between different vegetable families can reduce soil pathogens by providing a host plant. Basically, the use of cover crops in your vegetable gardening efforts will help you in my many areas plus increasing your overall garden production.

Cool season cover crops are normally planted from early September to early October after the summer garden is done producing. If you do not plan on planting any winter vegetables, you can plant your entire garden in cover crops. For a cool season cover crop, you need to think about a combination of a cereal grain along with a legume type.

Cereal grains suggested are wheat, oats or rye, and your legume options could be a clover or winter peas. Keep in mind that the cereal grains will be more aggressive or quicker to establish and the legumes will germinate slower. I want to add that you do NOT want to plant ryegrass for a winter cover crop.

Ryegrass is different that the cereal grain rye. Do not make the mistake of planting ryegrass because it will be very competitive and hard to get out of the garden area after establishment. Keep this in mind when making your cover crop purchases.

I will add that legumes will have the added benefit of fixing atmospheric nitrogen that can be used by the crop that is planted after you till the legume into the soil. This can actually reduce some of your need for fertilizer purchases. A common seed mix for a cool season cover crop would be 3-4 pounds of a cereal grain with .25 pounds of a legume per 1,000 square feet. If the garden spot is as large as an acre, you can use the rate of 50 pounds of a cereal grain and 5 pounds of clover per acre. I will add that nitrogen fertilizer should not be added to legume cover crops as this will interfere with the nitrogen fixation. If phosphorus or potassium is needed per a soil test, adding these can benefit the nitrogen fixation.

You may need legume inoculants in your activities. Keep in mind, per Westerfield, that specific Rhizobia bacteria will invade the roots of legumes thus forming nodules where nitrogen fixation takes place. These bacteria are specific for the different legumes and can be bought to inoculate legume seed prior to planting. The inoculant comes in the form of a powder and is live bacterial. Keep in mind there are specific inoculants for the different clover types and other legumes so get the right inoculant. You may ask at the store if the legumes are already inoculated.

Some gardeners may find the need for a summer cover crop next year if they are wanting to rest a part of the garden. The summer crops will also protect the garden from erosion and weed issues. Summer crop options can be buckwheat, millet, cowpeas, sorghum-sudangrass and soybeans. Depending on the seed you select, the planting rate can be 1-5 pounds of seed per 1,000 square feet. You can plant summer cover crops as a single seed option. If you do decide to mix seed in a combination, you should reduce the planting rate appropriately when mixing seed.

Next week, we will discuss planting and establishment of cover crops.