Cover Crop - Oats
$7.95 – $18.95
Avena sativa
Oats are a cool-season annual cereal grass that originated in the Fertile Crescent from its wild ancestor, Avena sterilis. Oats make a great cover crop whether you are looking to add biomass to your soil or offer forage to your animals. Its extensive fibrous root systems excel at erosion control and its upright growth habit can serve as a natural trellis for legumes. Oats suppress weeds and take up excess nutrients to hold them in place until your next crop is ready to absorb them as the oats decompose. Avena sativa, also known as common oats, is also used to make oatmeal, rolled oats, and milky oats! Oats typically grow 12-36 inches, sometimes even taller. Oats grow best in cool, moist conditions. Quick to germinate and mature given adequate moisture, oat seed can be sown in spring or fall. Broadcast the oat seed, rake them in shallowly, and keep the soil moist for rapid emergence.
Oats will winter-kill in much of zone 7 and colder, so if you plan on using it as a fall cover crop, we recommend sowing in late-summer or early fall, 6-10 weeks before your area’s average first frost. Once killed by hard frost, it can be left to act as a mulch to continue suppressing weeds, insulating the soil microbiome, and protecting the soil from erosion until spring at which point you can plant directly into the mulch if using no-till methods. It will not regrow in the spring like Winter Rye. In zones 8 and warmer where oats are likely to over-winter, when you are ready to terminate the cover crop, mow it to leave it on the surface as a mulch or till it in to incorporate it into the soil. Wait at least two weeks after killing the oats to plant your next crop. The same goes for spring plantings. Seeding rate: 4 pounds per 1,000 square feet.
For more information on all things cover cropping, check out our Learn to use Cover Crops page.
- How to Grow
- Saving Seeds
Why Grow Oats?
When grown as a cover crop, Oats provide erosion control, weed-suppression, additional biomass for your soil, and a natural trellis for legumes. This variety of Oats is also grown to produce oatmeal, rolled oats, and milky oat tinctures.
When to Seed Oats
Oat seed can be sown in spring or fall. For a spring planting, choose a bed that you don’t plan to otherwise use for at least 6 weeks. Look for your soil temperature to be at or above 40ºF. Ideal daytime air temperature highs would be around 60ºF and overnight lows would not drop below 40ºF within the first week of planting. Oat seedlings have been known to withstand down to 26ºF, but oat seeds do not germinate well below 40ºF. For fall plantings, sow oats 6-10 weeks before your average first frost date. In Asheville, NC, this means March and August are typically the best times to sow Oats.
How to Seed Oats
Broadcast Oat seed evenly over your planting area in the spring or fall. Lightly rake them into the soil after broadcasting. Water thoroughly at the time of sowing and continue to water consistently until the seeds germinate. Watering well is very important for good germination.
How Much Oat Seed Do I Need?
The seeding rate for Oats is approximately four pounds of seed per 1,000 square feet. That means one pound covers about 250 square feet, three pounds covers about 750 square feet, and five pounds covers about 1,250 square feet. You can measure your garden and use the following equation to calculate how many pounds of Oat seed you need based on the square footage of the space you want to cover: (4 lbs of Oat seed / 1,000 sq. ft.) x (square footage of your garden) = amount of Oat seed you need in pounds. If you buy extra, store the excess in a cool, dry, dark place and use it again another season.
How Often to Water Oats
Oats grow best in cool, moist conditions. Drought can cause oats to be stunted and not mature properly. If you are going through a dry spell, water oats thoroughly twice a week.
When and How to Terminate Oats When Used as a Cover Crop
With cover crops in general, it is good to terminate them at least two weeks before you intend to plant your next crops. Some cover crops including Oats produce allelopathic compounds which have a germination/growth suppression effect on many other plants, so two weeks between termination and planting can allow those effects to wear off. Two weeks also allows the cover crop to start decomposing, slowly releasing nutrients and making them available for the use of the next crop. Some methods for terminating Oats include mowing (cut as close to the ground as possible), tilling, or waiting for a hard frost to kill them (most of zone 7 and colder). Roller crimping is also an excellent way to terminate cover crops if you have access to that machinery or have a homemade crimping board. Mowed, winter-killed, or crimped Oats can be left on the surface to serve as mulch for your next crops.
If you are interested in saving seeds from your oat plants, this tab is for you! If you only want to grow oats for the purpose of cover cropping, you don’t need to worry about this information.
Whether you want to harvest oats for consumption or seed saving, you will grow and harvest oats in the same way.
Common oats are classified as long-day plants and require 12 hours of light in a day to promote flowering. Lucky for us, that is achieved at all latitudes in the U.S. Note that if oat plants are exposed to temperatures over 82 degrees Fahrenheit, especially with drying winds, oat flowers can abort. Oats do best in cool, moist conditions. Oats are primarily self-pollinating, which makes it easier to isolate varieties for seed saving purposes. A very small amount of cross-pollination can occur between Avena sativa (Common oats), Avena byzantina (Red oats), and Avena nuda (Naked oats) through wind. The standard isolation distance between different kinds of oats is 10 - 20 feet, but if you are saving seed to preserve the genetics of a variety, increase your isolation distance to 50 feet to confidently avoid cross-pollination. It is always best to save seed from as large a population as possible to maintain genetic diversity.
Oat seeds are mature and ready to be harvested when the hulls around the seeds turn a tan or cream color and the kernels inside are hard. Cut the plant about 4 inches above the ground. A sickle or scythe is great for this job. From there, if you’ve grown a large quantity, you can either windrow (rake into heaped rows) or bundle them into sheaves to dry in the field. If you’ve grown a small quantity, you can move them to a warm, protected place to dry. Let the oats dry for several days. Dry plants can then be threshed by beating them repeatedly against a hard surface until the oat grains separate from the stalk. If you have seed screens, the appropriate size to use for oat seeds is 5/64 to 22/64 inch (2 - 8.5 mm). Winnow to remove chaff and weed seeds. You should be left with pure oat seeds to save or eat!
If stored in a cool, dry, dark place, you can expect oat seeds to last at least four years.