How to Grow a Clover Cover Crop
There are many types of clover used for a clover cover crop, but some are better than others. We walk through the basics of getting started!
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When thinking of ways to improve your soil, most people wouldn’t think of planting additional crops, let alone one you wouldn’t normally eat. However, planting a clover cover crop is one of the easiest and most cost-effective ways to rehabilitate your soil.
Clover is related to other legumes like peas, beans, and peanuts. It’s most commonly found in temperate regions of the Northern Hemisphere but also grows in South America and Africa, where it occurs in a wide variety of biomes ranging from high-altitude mountains down to the coastal plain.
Sowing an annual crop of clover can make a huge impact on your soil health and is one of the easier cover crops to grow. Very much a “set it and forget it” type crop, once the clover starts growing, there isn’t much work for the gardener to do.
If you live in the invasive range of some clover plants, opt for an adapted species or another nitrogen-fixing cover crop instead.
White Clover Alternative Lawn Seed Shaker
White Clover Alternative Lawn Seed Shaker
Benefits Of Cover Cropping
First, let’s look at the concept of cover crops. What are they? Cover crops are plants you grow in your garden to cover the soil rather than for harvesting. There are many different types of cover crops, each with their own benefits and drawbacks.
No matter what type you use, cover cropping offers many benefits. The plant’s extensive root system protects soil from erosion and digs deep, improving soil tilth. Some plants, including clover, fix nitrogen in the soil and help suppress weeds. Early flowering crops bring beneficial insects to your garden when you need them most in early spring.
What Is Clover?
Most people are familiar with the four-leaf clover symbol and its associated luck, but did you know there are over 300 species of clover? Clover is believed to have originated in Europe but has since spread to all continents except Antarctica.
Closely related to peas, clovers are flowering legumes that tolerate many growing conditions, ranging from grasslands and alpine meadows to rainforests and, perhaps the most well-known, suburban lawns. Beyond its use as a cover crop, clover is commonly used as livestock feed, pasture for commercial beekeeping, and forage for a variety of wildlife. Native Americans used the leaves, roots, and seeds for food.
Why Does Clover Make A Good Cover Crop?
Clover makes an excellent cover crop for several reasons. The first is its affinity for nitrogen fixation.
Like many legumes, clover fixes nitrogen through a symbiotic relationship with bacteria in the soil. The bacteria form nodules on the clover roots, take nitrogen from the air, and convert it into a form the plant can use. The specific amount changes depending on planting conditions, local climate, and the variety of clover chosen.
The second reason clover works well as a cover crop is that it acts as a ground cover, protecting soil from both erosion and weeds. Clover establishes itself before other plants and newly germinated weeds can, acting as a natural form of weed suppression. The same rapid growth that helps with weed control also fights erosion by quickly covering a large area of the garden.
The third reason clover works so well as a cover crop is its use as green manure. This provides many benefits, such as keeping nutrients near the soil surface as it breaks down, acting as a mulch if left on top, building organic matter, and providing a home for beneficial insects and decomposers.
An often overlooked benefit of cover crops is their ability to bring in beneficial insects. Clover hits its flowering stage earlier than most plants, blooming early in the spring when beneficial insects like native bees, honey bees, and other pollinators need them most. Curating a well-balanced ecosystem of insects within your garden has massive benefits like pest prevention and drawing in pollinators for your other crops.
Choosing a Variety
There are more varieties of clover than could be reasonably listed here, so I’ll narrow it down to a few that are most useful and common in gardening and agriculture. Other than the variety you choose, there are two important factors to consider: lifecycle and time of planting.
Clover can be either annual or perennial, depending on both your local climate and the variety chosen. Annual types only reproduce via seed and need to be reseeded each year. Perennial clovers also reproduce from seed but become established in one area and regrow each year without extra work.
Whether you choose an annual or perennial depends on your needs. Most gardeners choose an annual variety since they’re planting clover as a cover crop and want to completely kill the plant before planting their garden. Perennial clovers work best when grown for livestock forage or permanent erosion protection.
The second consideration is the time of planting. While all clovers tolerate cool conditions, some gardeners choose specific varieties like a winter annual clover that will die back with heavy frost and re-emerge in the spring. If planting in mid-May or early summer, choose a variety that can handle hot weather and drought.
Varieties
One of the most dependable varieties is crimson clover, also known as scarlet clover. It is an annual that adapts to many climates and soil types. Crimson clover flowers earlier and grows throughout the winter more readily than other clovers. It forms tall, bushy flowers in a deep red or fuchsia color, and its seeds are readily available through most garden shops or seed distributors. Crimson clover is also a very efficient nitrogen fixer.
Red clover and white clover are both perennial varieties. White clover is the most widely grown variety in the United States, with many people recognizing it as the same species growing in their lawns. Red clover seed is larger, making it easier to collect when harvesting this crop seed. In areas where it is well established, red clover can be hard to kill, so keep that in mind before planting it as a temporary cover crop. In agricultural settings, a medium red clover stand is usually killed using a roller bar or moldboard plow attached to a tractor.
There is a sub-variety called mammoth red clover that grows several feet tall and features large seeds. Mammoth clover is a short-lived perennial that grows well in areas with low soil pH and poor fertility. A short-lived perennial has a lifespan of roughly three to five years before it needs to be reseeded.
Arrowleaf clover is used less commonly by home gardeners but makes excellent forage and hay for livestock. It grows in cold conditions and can quickly cover an area of pasture.
Planting
Clover can grow virtually anywhere in the garden but generally prefers well-drained soil that is slightly acidic. The plants tolerate shade but grow best and achieve maximum nitrogen fixation in full sun. Clover performs well in both raised beds and in-ground garden plots.
Choose a variety that works well for your climate and planting region. Crimson clover tends to adapt to most climates. Red clover grows well in warm climates, while white clover performs better in cooler, wetter climates.
If planting for a summer ground cover, sow in early spring near the time of the last frost. When planting to protect your soil over the winter, plant in late summer when the plants have about six to eight weeks before the frost date to become established.
Sow the seeds by distributing them over the garden plot by hand, then lightly rake over the soil. Clover seed germinates best when barely buried, so try not to push the seed deeper than ¼”. Keep the soil moist until the seedlings begin actively growing. Most clovers are quite tolerant of drought but do best with around ½” to 1″ of water per week.
Potential Issues
Being rugged, well-adapted plants, clovers don’t present too many growing concerns. When grown as cover crops, the risk is even lower since the plants are meant to be cut down before harvest, unlike other crops in the garden. Most issues come from overly damp conditions that set the stage for fungal attacks. Prevent this by planting an appropriate variety for your growing area and avoiding soils that hold too much moisture.
For most gardeners, the bigger risk is that the clover will set seed and accidentally reseed an area of the garden. Prevent this by carefully monitoring growth and cutting down or turning in the plants before they manage to seed.
Harvest For The Garden
For its use as a cover crop, there are three main ways to “harvest” clover. The first is the “chop and drop” method. It’s exactly as it sounds: you go through the garden with a large pair of shears, string trimmer, or any other cutting tool and chop the clover down, dropping it onto the soil. It can either be left there as a mulch or buried under a layer of compost or soil.
There is also the “chop, drop, and regrow” method, where you cut just the tops of the plants off, leaving the rest to regrow a second harvest.
The second method involves tilling the clover into the soil. This is common in both agriculture and gardening settings. Using a hoe, tiller, or other digging tools, till the plants into the top layer of soil. They will quickly break down and add nutrient-rich organic matter.
The last method is similar to chop and drop, but instead of leaving cuttings on the surface of the soil, you add them to your compost bin. This has the advantage of keeping debris out of the garden, and the compost bin can turn the cuttings into compost more quickly than if you had left them in the ground.
Frequently Asked Questions
What clover is best for a cover crop?
This is largely dependent on your climate and required uses in the garden, but crimson clover is a dependable variety that performs well in many situations.
Is clover a winter cover crop?
Yes! In most places, clover can withstand winter weather and re-emerge in the spring.
What is the best cover crop?
Choosing the best cover crop depends on your climate and your needs in the garden. Each type of cover crop has benefits and drawbacks.
