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The Many Benefits of Cover Cropping (Plus 7 Varieties We Love)
Once you have a couple of growing seasons under your belt, it’s time to turn your attention to cover cropping.
Cover crops are a group of grasses, legumes, and other plants that are cultivated during the off-season to improve soil health. These plants aren’t grown for harvest but are turned back into the soil at the beginning of the growing season, and are one of the best natural ways to improve soil health and plant productivity over time.
Keep reading for a more in-depth explanation of what cover crops are and how they work, plus our top recommendations for your garden–regardless of how much space you have to grow.
What are cover crops?
Cover crops are plants cultivated to improve the health of the soil, rather than for harvest.
The benefits of cover cropping are seemingly endless. Planting cover crops simultaneously improves soil structure and composition, slows erosion and surface runoff, suppresses weed growth, and attracts beneficial insects.
Cover crops add nutrients to the soil as they grow and die, improving soil texture and composition. Cover crops also have robust root systems that hold soil and purify water, increasing the soil's water-holding capacity. Over time, planting cover crops will naturally increase biodiversity in the garden and improve plant resistance to pests and disease.
You can think of cover crops like green mulch—it’s any plant that is grown to improve the soil structure and composition. Cover crops are typically sown in late summer or fall, left to grow through the winter, and disked back into the soil in early spring, but you can technically grow cover crops at any time of the year, or between crop rotations.
Outside of the obvious environmental benefits, planting cover crops has been proven to increase plant productivity and resilience. In one study conducted by the USDA, corn farmers had a 3.1% increase in yields when the corn was planted following a cover crop. Soybean farmers saw a 4.3% increase in yields.
Most soil issues can be fixed over time with the use of cover crops. Cover cropping is the best way to correct hardpan, the layer of packed soil that appears after years of heavy machinery have compressed the soil structure.
Choosing the right cover crop
There are four categories of cover crops: legumes, grasses, brassicas, and non-legume broadleaves. Legumes are nitrogen-fixing plants like peas, beans, clover, and vetch. Broadleaf species include buckwheat and flax, and brassicas like radish and mustard are commonly used as cover crops. Some examples of forage grasses are ryegrass and barley.
Legumes
Legumes are natural nitrogen fixers, so they reinvigorate the soil with nitrogen, making them the go-to choice for nitrogen-poor soils.
Unfortunately, legumes may also draw deer and other wildlife to your garden–so if you haven’t already, consider building a deer fence or planting a different cover crop.
These bright red blooms are as purposeful as they are beautiful, drawing pollinators to the garden in droves. An annual variety, Crimson Clover is easily tilled in at the end of its growth cycle, at which point it makes a lovely green manure that suppresses weeds and adds organic matter back to the soil.
A lovely alternative to red clover, White Dutch Clover is our most potent legume, fixing up to 170 pounds of nitrogen per acre! But that’s not all White Dutch Clover is good for–this low-growing perennial attracts beneficial insects and improves soil health.
Capable of fixing nearly as much nitrogen as clover, Hairy Vetch thrives in poor, acidic soils where clover doesn’t do as well. Hairy vetch is one of the hardiest legumes, making it ideal for growers with cold winters.
Broadleaf species
Some of the best cover crops to use for weed suppression are broadleaf varieties since their leaves block sunlight and inhibit weed seed germination.
One of our most popular cover crops, Buckwheat grows fast and it thrives in most soil types, so it’s the perfect cover crop for most gardens. Buckwheat is a great choice for weed suppression and pollinator attraction as well.
Brassicas
Yes, some vegetables make great cover crops–and you’ll get a bumper crop of root veggies, too.
You can use other varieties of radish as a cover crop, but Daikon is ideal for small spaces. The ten-inch, slender roots are excellent at breaking up compacted soils.
Grasses
Grasses add more organic matter and improve soil health, but if you let these cover crops go to seed you might end up with more weeds than you bargained for.
Although it may not be the first grass to come to mind, perennial grasses like Orchardgrass can make excellent cover crops. Perennial grasses have more extensive root systems than annual grasses and are even better at improving soil aeration.
Our 99% White Proso Millet strain has 80% germination, making it one of the purest and highest-quality millet strains on the market. Millet is ideal for hot climates with arid conditions, but it is sensitive to frost and won’t overwinter in colder climates.
The best cover crop for your garden will vary depending on your climate and your growing goals since different species will affect the soil differently. Check out our Farm and Field Seeds to see the full collection of cover crop seeds!
Of course, you can always plant a cover crop blend, and many cover crops are sold in mixes! Our Permanent Pasture Mixture makes an all-around excellent cover crop or pasture mix for grazing livestock.
Timing is key
Most cover crops are cool-season plants that prefer the colder temperatures that fall and winter bring. This means that the ideal time to sow cover crops is in late summer or early fall.
Most growers sow cover crop seed from mid-September to mid-October, but growers in colder climates may sow their cover crop sooner (August), while gardeners in milder zones have a longer window of time to plant cover crops (November through December).
Fall sowing gives the plants a headstart and results in healthier, more robust plants that bloom even earlier in the year. Plus, overwintering a hardy cover crop ensures that bare soil won’t be worn away during winter.
You can also sow cover crops in late winter or early spring, as soon as the soil is warm enough to cultivate. Spring-sown cover crops will need to grow until midsummer before being turned back into the soil, so it’s best to follow spring-sown cover crops with quick maturing annual crops.
Regardless of when you decide to sow a cover crop, it’s not a bad idea to order your cover crop seed early to ensure that it arrives with plenty of time to plant!
Calculating seed quantity
You don’t have to have a large field to plant cover crops—you can, and should, sow cover crops in any area you plan to grow in, no matter how small. Even raised beds and container gardens can benefit from cover crops!
These are our recommendations for cover crop seed quantity (per 500 square feet):
- White Clover: 2 ounces
- Crimson Clover & Hairy Vetch: ½ pound
- White Proso Millet & Orchardgrass: 6 ounces
- Buckwheat: 1 lb
At the Seeds ‘n Such online store, you can buy cover crop seeds by the ounce or by the pound depending on your needs. Try our recommendations first and adjust as needed for future seasons.
How to sow cover crop seed
The easiest way to sow cover crops is via broadcasting. If you have acres to cover, it might be worth investing in a seeder like this one, but for smaller plots broadcasting by hand is just fine.
Another cover crop seeding technique, interseeding, involves direct seeding cover crops while the current crops are still growing. A common example of interseeding is sowing a cover crop into a row of corn during the growing season.
Sowing cover crop in 5 easy steps
1. Prepare the soil
Before sowing cover crop seed, remove any weeds and kill any grass with a silage tarp. Lightly till the area or use a rake to disturb the soil, and clear the area of large sticks and rocks.
2. Prepare the seeds
Prepare a bucket with your cover crop seed, and inoculate legume seeds with Nitrogen Inoculant if needed.
3. Sow the seeds
Walk through the garden, scattering seeds evenly over the entire area to be planted.
4. Cover the seeds
Drag a rake back across the area to lightly cover the seeds.
5. Water the seeds
After seeding, water the area by hand or with a sprinkler system to jumpstart germination. Alternatively, check your local forecast and plan to sow cover crop seeds before or during rain.
Managing cover crops
Although cover crops might not need nearly as much attention as other plants, all cover crops benefit from some maintenance.
Fertilization
Penn State Extension recommends adding a balanced 10-10-10 fertilizer to the soil at the time you sow the cover crop, at ten pounds per 1,000 square feet. For legume cover crops, use a fertilizer with a lower nitrogen content and a 5-10-10 ratio.
Irrigation
Fall and winter precipitation will usually be enough to water cover crops unless you live in a drought-prone area. If you garden in a drier climate, run a sprinkler irrigation system for a few hours a week.
Tilling
You’ll want to cut the cover crop down right before it flowers and goes to seed, which is usually in early spring for a fall-planted cover crop. If you let a cover crop go to seed, you’ll have a weedy garden bed next growing season (and for many seasons to come).
Wait until the soil is workable, and then turn the cover crop back into the soil with a tractor and disking implement. It’s ideal to wait a couple of weeks after the cover crop is tilled in before planting summer crops—during this window the cover crop will decompose into nitrogen-rich organic matter.
Even though you never really harvest cover crops, you’ll reap the benefits of growing them for seasons to come. Cover crops naturally improve soil health and composition and naturally suppress weeds.
Planting a cover crop won’t cost you too much time or money, so why not give it a go? A healthier, more productive garden is just around the corner, so don’t put off ordering cover crop seeds any longer.
Shop our entire collection of Farm and Field Seeds today to make sure that you have your cover crop seeds in time for fall sowing!