10 Winter Cover Crops to Recharge Your Soil This Winter

Winter cover crops are one of the simplest ways home gardeners can protect and improve their soil during the off-season. While farmers have relied on cover crops for generations, more home gardeners are now using them in raised beds and in-ground gardens to reduce erosion, improve soil structure, and prepare beds for spring planting.

At Park Seed, we see the benefits most clearly in home gardens that are planted year after year. When soil is protected through fall and winter, it is easier to work in spring and better able to support healthy plant growth.

What Is a Winter Cover Crop?

A cover crop is a fast-growing plant sown to cover bare soil rather than for harvest. In home gardens, cover crops are most often planted in late summer or fall and left in place through winter. Their primary role is to protect the soil surface, support soil life, and contribute organic matter before spring planting.

What Are the Benefits of a Cover Crop?

Cover crops can be used in any garden, including raised bed gardens. The cover crop seeds are usually fast germinating and fast growing. The purpose of a cover crop is to literally cover the garden with a living blanket of plant matter to sustain soil life. Here are some of the benefits of a cover crop: 

• Prevent soil erosion by protecting bare ground from wind, rain, and snow
• Improve soil structure by reducing compaction and increasing air and water movement
• Add organic matter that helps sandy soils hold moisture and nutrients
• Support beneficial organisms such as earthworms and soil microbes
• Reduce winter and early spring weeds by limiting open soil
• Provide early pollinator resources when flowering is allowed in spring

In our gardens, we see the biggest difference in beds that would otherwise sit bare through winter. Even a simple cover crop can make spring soil easier to work and more resilient through the growing season.

How to Choose a Cover Crop Based on Your Soil and Goals

There are many cover crops to choose from, and each serves a slightly different purpose. Climate, soil type, and timing all play a role in deciding what will work best. In a home garden, it often makes sense to try more than one option. Different beds can benefit from different cover crops, and experimenting from season to season helps you learn what suits your garden conditions best.

For most home gardeners, annual cover crops are the easiest place to start. Annuals complete their growth cycle within one season or are winter-killed by cold temperatures, which makes spring cleanup more manageable. Perennial cover crops can be useful in larger systems, but they tend to require more effort to work back into the soil and can be slow to remove from smaller garden spaces.

Timing matters as much as plant choice. In northern regions, cover crops are usually planted in late summer or early fall to allow enough growth before frost. In warmer southern climates, planting can begin as soon as beds are cleared after harvest. Cover crops generally need about four weeks to establish before cold weather slows growth. When fall harvest stretches late, I often seed cover crops immediately after pulling a finished crop, or sow them between remaining plants so the soil is never left bare.

How to Decide What Type of Cover Crop to Use

Several cover crops are commonly used in home gardens, including clover, hairy vetch, winter rye, and oats. The best choice depends on your growing region and what you want the cover crop to accomplish. Most gardeners choose cover crops to improve soil fertility, reduce compaction, or add organic matter, and different plants support those goals in different ways.

Improving Nitrogen Levels

If restoring nitrogen is a priority, legumes are the most effective option. Cover crops such as clover and vetch work with naturally occurring soil bacteria to capture nitrogen from the air and store it in nodules along their roots. As the plant material breaks down, that nitrogen becomes available to future crops.

This process is similar to the way farmers rotate nitrogen-fixing crops with heavy feeders. In home gardens, legumes help reduce nutrient loss during winter and support stronger growth the following season.

Loosening Compacted or Clay Soils

For gardens with heavy or compacted soil, grasses such as oats and barley are useful because their root systems improve soil structure and water movement. These cover crops add organic matter but do not contribute nitrogen, so additional nutrients may be needed in spring.

Another effective approach is to plant a mix of cover crops. Pairing a grass with a legume combines soil-loosening roots with nitrogen contribution. Ready-made mixes are widely available, or you can create your own blend. Daikon radish is another option for compacted soil. Its large taproot grows deep into the ground, helping to open the soil and add organic matter as it breaks down.

Improving Sandy Soils

Sandy soils benefit from cover crops that add organic matter. As plant material decomposes, it helps the soil hold moisture and nutrients more effectively. Over time, this improves soil stability and supports more consistent plant growth.

Common Winter Cover Crops and Their Benefits

How Do You Sow a Cover Crop?

Till or loosen the top few inches of the soil and then lightly rake to give a good planting surface. Simply hand scatter the seeds over the area and rake in if the seeds are small. If the seeds are large, plant in rows that are close together. Cover with soil equal in depth as the size of the seeds and then tamp down gently with the back of the rake. Lightly water and cover with a thin layer of straw to protect the bed from heavy rain and wind while the seeds germinate. 

If you are planting legumes, you will want to use inoculant to guarantee the nitrogen fixing process. The inoculant is a bacteria called Rhizobium leguminosarum that causes the beans or peas to form the nodules and store the nitrogen. Without these bacteria, the plants may not have the nitrogen they need to grow as well as replenish the nitrogen in the soil. 

There are two ways to apply the inoculant. It can be added right to the soil as you plant the seeds, or you can apply it to the seeds directly. Simply pour the seeds into a water-filled dish to wet them and then roll them in the inoculant. Some gardeners add one part corn syrup to 10 parts hot water to the inoculant. Let it cool before using and then add the seeds, as this helps the inoculant to stick to the seeds.

Besides the rake and seeds, the inoculant is one of the only indoor garden supplies you will need to grow a cover crop. 

What Happens with Cover Crops in the Spring?

When early spring arrives and your perennial cover crops resume growing, many will want to let them flower and then set seed. The danger is that your cover crop could become a weed-like plant. The annuals will be dead from the cold, with some lying on top of the ground and others still standing. You now have three options: use the plant matter as a mulch, add the plant matter to the compost bin or dig the plant matter into the soil. 

Regardless of which you choose, it is best to cut the organic matter into smaller pieces so it can be utilized in the soil sooner. Depending on what type of cover crop you planted, you can chop it up with garden shears, a string trimmer or you can even use a mulching mower. If your cover crop is a nitrogen fixer, don’t pull the roots out of the ground. Once you have chopped the plant material, remove it to the compost bin. You can also leave it on the surface of the soil and simply move it over when the time comes to allow planting. 

If you want to improve the soil with the organic matter, either work it into the soil with a garden fork or use a rototiller. You should wait two to three weeks before you plant so the breakdown of the material can proceed and the benefits of the organic matter you added — as well as the nitrogen fixing — can set in.

Which Type of Cover Crop Should I Choose for My Garden?

These are some cover crops you may want to consider trying in your garden:

Hardy Legumes

These cover crops will add organic matter to your soil, and they will increase the nitrogen. You should be sure to mow these down before they flower in the spring.  Some hardy legume options for you to consider include:

1. Crimson Clover—Grows 18 inches high and is hardy to 10 degrees. Crimson Clover will fix nitrogen and attract bees. Be sure to mow before it goes to seed or it can become weedy.
2. Berseem Clover— Will grow one to two feet tall and will regrow after cutting. This type of clover is hardy to 20 degrees and produces large amounts of nitrogen.
3. Hairy Vetch— Hardy to -15 degrees, this is the hardiest annual legume that grows to two feet tall and is proficient at fixing nitrogen in the soil. This plant can have so much top growth that it is hard to turn over by hand. You will need a good mulching mower and probably need to be prepared to till the soil after it is chopped.

Tropical Legumes

These legumes need warm weather to grow. They can be planted as a cover crop in the southeast and southwest parts of the country. They will produce a large amount of organic matter and increase the level of nitrogen in the soil. Northern gardeners will need to plant this as a summer annual.

• Some tropical legume options for you to consider include:
  1. Cowpea— This legume prefers humid warm temperatures and is hardy to 32 degrees. Cowpeas will grow one to two feet high and can be used to stop erosion and block out weeds.
  2. Sunn Hemp— Grows five to six feet tall and needs the same growing conditions as corn. Hardy to 28 degrees, this cover crop needs to be cut up before the stem becomes woody.

Grasses

Grasses don’t add nitrogen to the soil, but they do help if you have compacted soil and they tolerate cold temperatures. Grasses are great for controlling erosion, but these are annuals so cut them down before they set seed and/or till them under. Some grass options for you to consider include:

1. Winter Rye — Grows four to five feet tall, this is the best grass if you live in the north as it will tolerate temperatures as low as -20 degrees. It is a great choice for preventing erosion from wind and water. This grass has very fibrous deep roots and can be difficult to turn over in the spring. Use a mulching mower and till the organic matter into the soil.
2. Oats— Grows two to three feet tall, this grass is tolerant of wet soil and temperature as low as 10-20 degrees. This cover crop is great at preventing soil erosion and it loosens heavy soils.
3. Barley— Grows two to three feet tall, this grass is tolerant of dry soil and temperatures as low as 0-10 degrees.

Other Annual Cover Crops

These cover crops will produce a lot of organic matter, but they will not increase the nitrogen levels. Some other cover crop options for you to consider include:

1. Buckwheat — Grows one to three feet tall and is tolerant of temperatures down to 32 degrees.
2. Brown or Black Mustard— This plant has a strong taproot but can become a problem weed in the garden. Tolerant of temperatures as low as 0 degrees, this plant will grow to one to three feet tall. Mustard plants are attractive to the bees. 

Let this be the year that you use a cover crop to protect your garden soil and improve its condition. Decide which one will meet your priorities or even try a mix of different cover crops in the same area. The benefits could be a game changer in your garden.