Sweet Clover

These are annual or biennial plants.  There are two varieties, yellow and white. They form arbuscular mycorrhizal associations, attracts pollinators, moderate water use and fair salinity tolerance.  Sweet clovers within a single season on even marginally fertile soils, can produce abundant biomass and moderate amounts of nitrogen as it pushes its taproot and branches deep into subsoil layers.  Given fertile soils and a second season, it reaches its full potential for nitrogen and organic matter production.  Early in the second year it provides new top growth to protect the soil surface as its roots anchor the soil profile.  It is the most drought-tolerant of forage legumes, is fairly winter-hardy and can extract from the soil then release phosphorous, potassium and micronutrients that are otherwise unavailable to crops.  It thrives in temperate regions wherever summers are mild.

Annual sweet clover is not frost tolerant, but can produce up to 9,000 pounds of dry matter per acre over a summer after being over sown into a grain crop or direct seeded with a spring grain nurse crop.  Its taproot is shorter and more slender than that of its biennial cousins, but it still loosens subsoil compaction.

Subterranean Clover

Subterranean clovers offer a range of low growing, self-reseeding legumes with high N contribution, excellent weed suppression and strong persistence in orchards and pastures.  Most cultivars require at least 12 inches of growing-season rainfall per year.  A dry period in the summer limits vegetative growth, but increases hard seed tendency that leads to self-reseeding for fall reestablishment.  They generally grow close to the ground, piling up their biomass in a compact layer.  There are many cultivars that can be selected from to fit your climate and cover crop goals.  Sub-clovers can produce 3,000 to 8,500 pounds of dry matter per acre in a thick mat of stems, petioles and leaves.  Denser and less viny than hairy vetch, it also persists longer as weed-controlling mulch.  Subterranean clovers might be able to be utilized by planting them with cereal crops as a living mulch and nitrogen provider.

White Clover

White clovers are a top choice for “living mulch” systems planted between rows of irrigated vegetables, fruit bushes or trees.  They are persistent, widely adapted perennial nitrogen producers with tough stems and a dense shallow root mass that protects soil from erosion and suppresses weeds.  Once established, they stand up well to heavy field traffic and thrive under cool, moist conditions and shade.  Cultivars are grouped into three types by size.  The lowest growing type (Wild White) best survives heavy traffic and grazing.  Intermediate sizes (Dutch White, New Zealand White and Louisiana S-1) flower earlier and more profusely than the larger types are more heat-tolerant and include most of the economically important white types.  The large (Ladino) types produce the most N per acre of any white types, and are valued for forage quality, especially on poorly drained soil.  They are generally less durable, but may be two to four times taller than intermediate types.

White clover performs best when it has plenty of lime, potash, calcium and phosphorus, but it tolerates poor conditions better than most clovers.  Its perennial nature depends on new plants continually being formed by its creeping stolons and, if it reaches maturity, by reseeding.

Red Clover

Red clover is a dependable, low-cost, readily available workhorse that is winter hardy in much of the U.S.  Easily over seeded or frost seeded into standing crops, it creates loamy topsoil, adds a moderate amount of N, helps to suppress weeds and breaks up heavy soil.  It’s most common uses include forage, grazing, seed harvest, plow down N and, in warmer areas, hay.  It’s a great legume to frost seed or inter seed with small grains where you can harvest grain as well as provide weed suppression and manage N.

Berseem Clover

Berseem clover is a cool season annual legume.  It is commonly known as Egyptian clover.  It has fair salinity tolerance, low water use; forms arbuscular mycorrhizal associations and the flowers attract bees.


Vetch is a cool season annual or biennial legume.  It grows very prostrate (viny).  There are several types, common, hairy, purple, smooth, woolypod, etc.  They are characterized by low to medium water use and poor salinity tolerance.  They form arbuscular mycorrhizal associations and attract pollinators.  They are some of the most dependable cool season annual forages.  They do tolerate acid soil, but not poor drainage.  The large seeds can emerge through thatch.

Closeup picture of Common Vetch showing the larger leaves and stems as compared to Hairy Vetch.


Common Vetch has a low percentage of hard seed produced, so it may be less likely to become a nuisance weed.  This cultivar flowers from April to July, and matures from May to July.  It tolerates many soil types, but needs good drainage.  The seedlings apparently establish through dense litter better than do those of woollypod vetch, purple vetch, burr medic, subterranean clover, or crimson clover.  Honeybees seldom visit the large blooms.  It is suitable in areas with mild winters and often winter kills in the northern part of the cotton belt; it may be slightly more cold resistant than purple vetch, but does not grow as rapidly during the winter.  It quickly succumbs in hot weather, so should be planted in the fall and harvested in the spring.  Taproots can extend 3-5 feet deep as well.


Hairy Vetch is a winter annual or summer annual legume.  Few legumes match hairy vetch for spring residue productions or nitrogen contribution.  It is widely adapted and winter hardy through Hardiness Zone 4 and into Zone 3 (with snow cover); hairy vetch is a top N provider in temperate and subtropical regions.  It grows slowly in the fall, but root development continues over winter.  Growth quickens in spring, when hairy vetch becomes a sprawling vine up to 12 feet long.  Height rarely exceeds 3 feet unless the vetch is supported by another crop.  Its abundant, viny biomass can be a benefit and a challenge.  The stand smothers spring weeds, however, and can help you replace all or most N fertilizer needs for late-planted crops.  It delivers heavy amounts of mineralized N which are readily available to the following cash crop.  It is sufficient for many vegetable crops and will partially replace N fertilizer for corn or cotton and increase cash crop N efficiency for higher yield.

Field Peas

Field Peas are another very good option for the area.  There are spring and winter options for these, as well as those bred more for grain or forage types.

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