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Plant Vetch as a Cover Crop and Reap the Benefits


If you are looking for a workhorse cover crop, look no further than vetch. Few legumes contribute as much nitrogen or biomass to the garden. Vetch produces an abundance of vining stems and fine foliage that help protect soils from wind and rain, while improving structure and adding nutrients. Plant vetch as a cover crop or green manure and reap the rewards of healthy, thriving soil.

Plant Vetch to:

  • Plant Vetch to Fix Nitrogen in the Soil
  • Plant Vetch as an Ideal Cover Crop
  • Plant Vetch to Reduce Stormwater Runoff
  • Plant Vetch to Combat Weeds
  • Plant Vetch for its Adapatbility
common vetch
Common Vetch is an ideal cool-season cover crop.


Plant Vetch to Fix Nitrogen in the Soil

All plants need nitrogen to grow. Nitrogen is an essential component of proteins, DNA, and chlorophyll, the compound used to power photosynthesis. Without nitrogen plants could not produce or use energy and life as we know it would not exist. Luckily, our atmosphere is composed of 78% nitrogen. But plants can’t use nitrogen from the air. That’s where legumes come in.

Legumes are plants belonging to the bean and pea family. These plants contain beneficial bacteria called Rhizobia within nodules on their roots. With the help of Rhizobia, legumes fix nitrogen, converting atmospheric nitrogen from the soil into organic compounds that the plants use to grow. When the legumes die, the ‘fixed’ nitrogen is then released into the soil where it can be used by other plants. This is a natural source of fertilizer often called green manure.

There are many types of legumes with varying capacity to fix nitrogen. Among these, vetch is among the most productive and is widely used in crop rotations. It is important to remember that all legumes must have the associated Rhizobia present in order to fix nitrogen. While Rhizobia is naturally present in many soils, it is best to purchase inoculated seed or treat seed with Rhizobium inoculant prior to sowing vetch.

vetch seed size comparison
Common Vetch Seeds
crown vetch seed size comparison
Crown Vetch Seeds
hairy vetch seed size comparison
Hairy Vetch Seeds


Plant Vetch as an Ideal Cover Crop

In addition to fixing nitrogen, a vetch cover crop improves soil health and structure. Hairy vetch and common vetch are widely used as cool-season cover crops. They are annuals that can easily be killed when time comes to plant the main crop. Crown vetch is an extremely aggressive perennial that is used for erosion control, not as a cover crop.

The root systems of cover crops like vetch condition soils by maintaining pore spaces that allow for air and water movement. This helps improve the tilth or loose, crumbly structure of the soil. In comparison, bare soils often become compacted, pore spaces are compressed, and movement reduced.

Vetch grows very quickly and produces a vast amount of plant tissue that contribute to the organic matter or biomass of soils. When vetch dies, the tissues breakdown quickly and thoroughly, releasing nutrients into the soil. In addition to nitrogen, vetch provides more phosphorous than many other cover crops.

Mature vetch can be used in a number of ways to improve soils. Vetch is typically killed in the early flowering stage to prevent plants from going to seed. Plants are easily killed by cutting stems at ground level. It is best to cut vetch two to three weeks before planting a crop.

Cut tissue can be incorporated into the soil as a green manure or left on the soil surface to serve as a mulch. Incorporation adds organic matter and improves soil structure, promoting good drainage and increasing a soil’s ability to retain water and nutrients. Using vetch residue as a mulch helps to retain soil moisture otherwise lost to evaporation and provides weed suppression.

Vetch Seeds


Plant Vetch to Reduce Stormwater Runoff and Soil Erosion

Cover crops provide another important benefit to the landscape: they reduce soil erosion. Exposed soils are easily washed away by wind and rain, robbing the garden of a rich growing medium. Eroded soil is typically deposited in streams, rivers, and lakes where it reduces water quality and habitat. Pesticides and fertilizers carried with the soil are a significant source of water pollution.

Plant vetch to stabilize soil and reduce erosion. In gardens and fields, hairy and common vetch make ideal cover crops during the fallow season. Plant roots and vegetation protect soils from wind and water. Crown vetch provides excellent erosion control on steep slopes and other areas where plants are difficult to establish.

Cover crops reduce stormwater runoff by maintaining a porous soil where water can infiltrate freely. Rather than sheeting across the soil surface, rainwater penetrates the soil and moves down into the water table. Increased infiltration also prevents water from standing or pooling on the soil surface which leads to the formation of a hard soil crust.

crown vetch
Crown Vetch is an aggressive perennial, and should not be used as a cover crop, but is great for erosion control.


Plant Vetch to Combat Weeds

Hairy and common vetch grow rapidly in the spring, outcompeting early-season weeds for sun and water. Such competition provides a low-maintenance form of weed management for the spring garden.

Vetch residues left on the soil surface after cutting continue to suppress weed growth by shading soils and smothering new growth. This benefit lasts about three to four weeks as the crop establishes and vetch decomposes, releasing nitrogen into the soil. Vetch is commonly used in this way as a mulch for tomatoes.

Vetch can also be used as a living mulch alongside cool-season crops like broccoli and cabbage. Actively growing alongside the crop, vetch provides nitrogen and battles weeds. Vetch is also planted in orchards such as pecan groves to attract beneficial insects. Lady beetles, big-eyed bugs (Geocaris spp.), and pirate bugs (Orius spp.) are prominent among vetch. When left to flower, vetch also attracts an abundance of honeybees and native bee species.

common vetch
Common Vetch
hairy vetch
Hairy Vetch
crown vetch
Crown Vetch

Plant Vetch for its Adaptability

Vetch is widely adaptable to diverse growing conditions. Though it requires water for establishment and to resume growth in spring, vetch is relatively thrifty when it comes to water needs. Plants tolerate a range of soil conditions and have low fertility needs. Several species are commercially available, each with unique benefits.

Hairy vetchVicia villosa, is the most winter hardy and drought tolerant of the vetches. Used primarily as a winter cover crop, hairy vetch is sown through late summer and into fall. It grows slowly during autumn and continues root development through the winter months. Hairy vetch is quick to grow in spring, producing vast biomass that smothers weeds and feeds soils. Hairy vetch can become weedy if left to produce seed. Careful management can prevent this problem. Simply mow or cut plants in late spring or early summer before flowers mature.

Common vetchVicia sativa, does not produce as much seed as hairy vetch, posing less of a risk of becoming weedy. However, it is also less winter hardy than hairy vetch. Common vetch has the most vigorous spring growth, producing an abundance of biomass and nitrogen making it an outstanding cover crop.

Crown vetch or crownvetch, Coronilla varia, is not a true vetch but closely resembles hairy and common vetch. This plant is a cool-season perennial, spreading by rhizome as well as seed. Crown vetch is extremely aggressive and should not be planted where desirable plants are established. Used primarily for erosion control on where other plants won’t establish, crown vetch quickly covers ground to anchor slopes and other erosion-prone areas. Because this vetch is grown as a perennial, we also get to enjoy the benefits of beautiful purple and white flowers that support a range of pollinators including honey bees, bumble bees, and solitary bees. While common and hairy vetch are widely used as forage crops, crown vetch is poisonous to livestock. Carefully research individual species when selecting forage for your animals.