No-Till Cover Crops: How To Grow Healthier Soil Over Winter

Close up of grass shoots growing out of soil
(Image credit: sbayram)

Many backyard gardeners avoid planting cover crops because it seems so hard to till them into the soil the next spring without all of the appropriate equipment. That’s where it pays to read about no-till cover crops. These crops give you all the benefits of cover crops, improving your soil over winter, but you don’t have to worry about blending them in.

If you’re wondering how to use no-till cover crops in vegetable gardens, just keep reading.

What Is a No-Till Cover Crop?

Cover crops are plants sown into soil after the ordinary growing season is over. These crop seeds, often a mix of grasses and legumes, sprout, grow, and produce biomass. They are then tilled into the soil to enrich it before the ordinary growing season.

In no-till gardens, the cover crop is carefully selected so that it maximizes the benefits of cover crops. No-till cover cropping stays planted until just before the vegetable crops are planted, and can be blended into the soil without tilling them. They either die after mowing or rolling, or die back naturally over the course of the winter.

Benefits of Cover Crops

Farmers have been using cover crops for many decades. Planting soil with a cover crop after the “cash crop” is harvested builds the soil’s organic matter, suppresses weeds, prevents erosion, moderates soil temperatures, increases soil fertility, and assists and encourages pollinators and beneficial insects. In the garden, the presence of the cover crop roots all winter increases space for water storage, makes the soil permeable, and recycles nitrogen and phosphorus in the soil.

Winter cover crops, planted in late fall and terminated in spring, are critical to organic farms and gardens where chemical fertilizers and pesticides are not permitted.

Benefits of No-Till Cover Crops

Regular cover crops are tilled into the soil before the primary crop is planted, often with a rototiller. But this can lead to overtillage, which weakens and disrupts soil properties, including the soil’s microbial community. That community is what holds nutrients, carbon, and water in the soil, increasing the potential for erosion and hastening the loss of organic matter.

No-till cover crops do not need to be tilled into the soil. That means they have all the normal benefits of cover crops but do not require the mechanical blending with the soil to be effective.

Best Cover Crops for No-Till Gardens

There are more than a few no-till winter cover crop species from which a gardener can choose. Each one has its management requirements and specific benefits.

Generally, a combination of grass and legume is used. This combination results in increased biomass production which means greater thickness of the cover crop mulch, meaning more weed suppression and available organic matter. The combination grass/legume offers a balanced carbon to nitrogen ratio, which, in turn, provides for a gradual release of nitrogen.

How to Use Cover Crops in a No-Till Garden

Essentially, cover crops serve to enrich your soil, allow it to store more water, and protect the space from weeds and excess temperature changes. The crops are sown into the soil after the garden crop has been harvested and stays until the next vegetable crop is ready for planting. At that point, the living cover crop plants are terminated. In no-till with cover crops, termination does not include mechanical tilling.

How to Plant a Cover Crop in a No-Till Garden

If you are wondering how to use cover crops in a no-till garden, the basic method is to prepare the soil, plant the no-till cover crop, allow it to grow and then terminate it. But there are a few tips to follow to make the process easy and effective.

In the fall when your vegetable crops are harvested, resist pulling out the plants by the roots. Rather, cut them at the soil line and dispose of this plant material. Leaving the roots in the soil will allow them to decompose, adding even more organic matter to the soil. In the spring, it is easy to lift out any remaining stems. Then you can employ a garden fork to break up compacted soil, mix in amendments, and otherwise get ready for planting.

No-Till Cover Crop Termination Methods

Like other cover crops, no-till crops must be terminated before planting the spring vegetable crop. Different methods of termination are used with different crops. The three primary means of terminating no-till cover crops are:

  • The crops die and form a mulch when they are mowed or rolled
  • The crops regularly are killed by winter weather
  • The crops regularly die back naturally before vegetable planting time
Teo Spengler

Teo Spengler has been gardening for 30 years. She is a docent at the San Francisco Botanical Garden. Her passion is trees, 250 of which she has planted on her land in France.