Trifolium hybridum L.

Short-lived, perennial legume. Utilized for pasture and hay production in mixtures with other legumes and cool-season grasses.

Semi-erect growth habit with fine stems, typically 1-3 feet (~30-90 cm) tall. Seed head is similar to white clover but more pinkish-white. Hairless stems and leaves. Palmately trifoliolate leaf with serrated leaflet margins without markings. Stipules are continuously tapering, with greenish veins, and sharply pointed. Many-branched, deep tap root to 4 feet (130 cm). 

Requires 25-40 inches (635-1000 mm) of precipitation or irrigation. Low heat and drought tolerance and moderate winter hardiness. 

Well-suited to wet conditions and soils high in clay content . Tolerates long spring flooding (7-30 days). Tolerates strongly acid soil conditions (as low as pH 5.1). Moderately sensitive to salinity (1.5-3 dS/m).

Easy to establish, but must be seeded no deeper than ½ inch (1.25 cm) at 2-3 lb/a (~3 kg/ha) if drilled in a mixture with a grass. Moderate fall grazing to leave 2-4 inches (5-10 cm) of residual dry matter is recommended. Can cause bloat and photosensitization. Not recommended for horse pastures.

Trifolium vesiculosum Savi

Winter annual legume. Suitable for hay, grazing, seed production, soil improvement, and wildlife forage.

Large conical flower head up to 2 inches (5 cm) long has white to pink flowers opening from bottom to top, turning brown when mature. Mostly upright stems grow to 3-4 feet (90-120 cm), are not hairy; are hollow, smooth, and often purple. Palmately trifoliolate, arrow-shaped leaves have a characteristic large, white V mark. Stipules are white, long, narrow, and pointed, with prominent veins. Deep taproot can penetrate up to 4.5 feet (140 cm). Seeds are about twice the size of those of white clover. Nearly 70% are hardseeded; seed requires scarification for satisfactory germination.

Arrowleaf is grown throughout the Midsouth and southeastern United States. It requires 18-25 inches (450-650 mm) minimum precipitation or irrigation. Tolerates moderately acid to moderately alkaline soils (pH range 5.6-8.4) that are well- to moderately well-drained. It is not suited to light-textured, droughty soils with low fertility and will not survive poorly drained, wet soils. It is moderately sensitive to salinity.

Overseed into warm-season perennial pastures for spring grazing. Plant 5-10 lb/a (6-12 kg/ha) scarified seed in September to early November. Graze when plants are 5-6 inches (10-12 cm) tall. Maintain a minimum canopy height of 3-6 inches (8-15 cm).

Improves pasture quality when overseeded into warm-season (C4) grasses. Minimal bloat risk.

Balansa Clover leaves inflorescence - Serkan Ates
Trifolium michelianum L.

Winter annual legume used for grazing, hay, silage, and as a cover or green manure crop.

Erect growth habit, typically to 3 feet (~1 m) but stems can reach 12 feet (3.7 m).

Cylindrical or conical seed head with many small white-pink florets. Fine, trifoliolate leaves can have smooth or serrated edges, with varying shaped leaflets. Taproot and numerous fibrous roots extend 30-35 inches (75-90 cm) deep. Seeds range in color from yellow to red-brown and black. Produces large amount of small seeds (0.8–1.2 mg/seed) with up to 98% hard-seededness.

Adapted to Mediterranean (summer-dry) climate but tolerant of cold winter temperatures [to -14 °F (-26 °C) USDA Plant Hardiness Zone 5b]. Heat tolerance to July mean maximum temperatures of 79-82 °F (26-28 °C). Early-flowering varieties can be grown in drier areas (14 inches, ~350 mm, annual rainfall). Tolerates strongly acid to moderately alkaline (pH 5.0-8.6) and mildly saline soils (3-5 dS/m). Can grow on high clay soils to sandy soils, and tolerates water-logged soils and brief periods of flooding.

Not strongly competitive until roots are established, so weed control is necessary if sown as a monoculture for hay or with fast growing species. Can be broadcast with fertilizer in low rainfall areas (300 mm) where open ground allows it to establish with little competition. Use 5 lb/acre (5.6 kg/ha) pure live seed if drilled and 8 lb/acre (9 kg/ha) if broadcast. For mixtures, use 3 lb/acre if drilled and 5 lb/acre if broadcast (3.4 and 5.6 kg/ha).

Berseem Clover inflorescence bee leaves stipules - CV Frosty - Hall
Trifolium alexandrinum L.

High-quality, fast-growing summer or winter annual legume. Also known as Egyptian clover.  Mostly erect stems that grow to 4 feet (1.2 m). Similar nutritive value to alfalfa without causing bloat. Good protein source grazed fresh or cut for hay and/or ensiled. Also used as a cover and green manure crop due to vigorous growth and nitrogen-fixation. Can be used as a “nurse crop” for alfalfa plantings or inter-seeded into declining stands.

Inflorescence is a head with cream to yellow-colored flowers. Leaves have oblong, pubescent leaflets. Stipules are pointed with red and green veination. Stems are hollow and pubescent, branching from the base. Pods contain a single purplish-red seed similar in size to crimson clover seed. Has shallow taproots.

Most cultivars are not tolerant of frost and will winterkill in continental climates (upper mid-west). Although ‘Bigbee’ a higher percentage of hard seed and greater winter hardiness than some cultivars it suffers cold injury at 25 °F (-4 °C) and winterkills prior to the new, cold-tolerant cultivar ‘Frosty.’ These more cold-tolerant cultivars are used in small grain>corn>soybean rotations in the Midwest, with good regrowth following oat companion crop harvest.  For use as a green manure crop in mild climates, ‘Multicut’ contributed an average of 280 lb N/acre (314 kg/ha) in a six-year trial in California with six cuttings per year. As a grazing crop in the south, ‘Bigbee’ produces longer into the spring than other legumes, extending cuttings into late May or early June in Mississippi.

Cultivar ‘Joe Burton’ is resistant to virus. ‘Bigbee’ is susceptible to crown rot and other root diseases. Berseem clover show little resistance to root-knot nematodes.

Cultivar ‘Frosty’ is a cold-tolerant berseem clover, recently reported to have survived -16 °F (-27 °C) under snow in Purdue University trials.

Used as a winter annual in mild climate areas [USDA Plant Hardiness Zones (PHZ) 6b-12a and as a summer annual in colder areas (PHZ 2b-5b). Less drought tolerant than alfalfa. In non-irrigated systems, requires a minimum of 40 inches (1000 mm) annual precipitation, with yield proportional to available moisture.

Best suited to medium-silt loam to clay-loam soils. Tolerates wet, poorly drained soils. Suitable pH range 6.5 to 7.5. Tolerates saline conditions better than red clover or alfalfa.

For pure stands, seed 8-12 lb/a (9-13.5 kg/ha) if drilled, 15-20 lb/a (17-22 kg/ha) if broadcast. Oats can be used as a companion crop; 30-60 lb/a (34-67 kg/ha). Use 3-5 lb/a (3.4-5.6 kg/ha) in mixtures. With irrigation, production potential is up to 8 tons DM/a. In grazing systems, graze before flowering when 12-15 inches (30-38 cm) tall and basal shoots begin to grow and no closer than 3 inches (8 cm). For hay or silage, cut at 50-60 days after planting (when companion crop is in early heading stage).

Most berseem clover cultivars die when exposed to temperatures below 20 °F (-7 °C) for several days. To kill berseem clover prior to planting fall crops, wait for it to die after blooming, use multiple diskings or apply herbicides. Rolling killed less berseem clover than hairy vetch or crimson clover when the legumes had more than 10 inches (25 cm) of stem lying on the ground.

Does not cause bloat.

Crimson clover inflorescence and leaves - Hannaway
Trifolium incarnatum L.

Winter annual herbaceous legume. Used to extend spring grazing in warm-season perennial grass pasture systems. Valued as a cover and green manure crop.

Inflorescence is a scarlet (or occasionally white) conical head. Leaves oval with no water marks, densely covered with hairs. Stipules are violet-veined, reddish-tipped and mostly fused with the stem. Taproot and numerous fibrous roots 12-20 inches (30-50 cm). Seeds are yellow, larger and more rounded than red clover seed.

Widely grown from Kentucky southward and from eastern Texas to the Atlantic Coast (USDA Hardiness Zones 6-9) and in the Pacific Northwest and California. Requires 30 inches (760 mm) of rainfall. Does not tolerate extreme heat or cold. Tolerates strongly acid to moderately alkaline soils (pH 5.1-8.4). Grows best on well-drained, fertile, loamy soils, but tolerates excessively drained to moderately well-drained soils. Tolerates only brief periods of flooding.

As a winter annual, seed 6-8 weeks before first frost date. As a summer annual, plant as soon as all danger of frost is past.

Highly nutritious forage. Use in mixtures with grasses to reduce risk of bloat. Harvest hay promptly as it begins to bloom.

 

Gland Clover - closeup flowering stem leaflets - Avinoam Danin - Flora of Israel
Trifolium glanduliferum Boiss.

Gland clover is an erect to semi-erect, extensively branched, very early maturing, self-regenerating annual legume species native to Turkey and Asia. Sown with other pasture species as a component of long-term pastures or in short-term cropping rotations.

Herbaceous, annual plant, growing to 20 inches (50 cm). Inflorescence is a clustered head of 30-50 flowers that change color with maturity; pinkish-white in early stages to a deeper pinkish-mauve color. Seeds are small, yellow, with oval shape.

Trifoliolate leaves have finely toothed, smooth, hairless leaflets. Leaflet margins contain glands. Stipules are oval, serrated, and green-veined. Stems are smooth and green, with some reddening on upper portions of stems and peduncle. Branched taproots to 30 inches (75 cm).

Cultivar Prima is early maturing and has high resistance to mites and aphids. It has small, hard seeds, preventing out-of-season germination.

Tolerates light frosts of 25 oF (-4 oC). Use in USDA Plant Hardiness Zones 8a-10b (minimum temperature of 10 oF (-12 oC). Suitable for growing in regions with 14-24 inches (350-600 mm) annual rainfall.

Tolerantes strongly acid to moderately alkaline pH (4.5-8.0) and somewhat poorly drained soil. Moderate tolerance of salinity (3-5 dS/m).

In a mixture with other legumes and grasses, use 1.8-3.6 lb/ac (2-4 kg/ha). In pure stands, use 4.5-6.3 lb/ac (5-7 kg/ha). Inoculate with Type C rhizobia for successful nodulation.

Can be heavily grazed in winter. Reduce stocking rate at flowering time to allow the clover to set large amounts of seed building up a soil seed bank.

Has high quality forage (22% crude protein, 75% digestibility). No livestock disorders have been reported but, as with many temperate legumes, could be expected to cause bloat in cattle.  Contains low levels of coumarins (lower than alfalfa); do not feed moldy hay to livestock. No major diseases. Resistant to red-legged earth mites, bluegreen aphids and cowpea aphids. Moderately susceptible to spotted alfalfa aphid and alfalfa flea.

Kura (Caucasian) Clover - Hollander
Trifolium ambiguum M. Bieb.

Long-lived, rhizomatous perennial legume also called Caucasian clover.

Used primarily for grazing, but provides forage and perennial cover as a living mulch. Persists under continuous stocking. High nectar content attracts bees. 

Inflorescence is a large, pink head. Flowers are white, turning pink-purple. Stems are solid, with few hairs. Leaves are palmately trifoliolate. Leaflets are soft, smooth, with variable pale green markings, numerous branched veins, and toothed margins. Stipules are broad, gradually tapering to a point. Roots to 3 feet (100 cm) are highly branched with extensive rhizomes.

Seeds are yellow or red-brown and roughly the same size as those of red clover. They are larger than white clover seeds.

Very winter-hardy, surviving extreme winter conditions; suited to plant hardiness zones 3a-8. Greatest productivity with 25-40 inches (635-1000 mm) of precipitation or irrigation. Excellent drought tolerance. Persists well on poorly drained soils; tolerates long spring flooding. Tolerates strongly acid soils (pH 5.1-7.3); is moderately sensitive to salinity (1.5-3 dS/m).

Low seedling vigor demands good weed control, thorough seedbed preparation, and good seed-soil contact for successful establishment. Seed no deeper than ½ inch (1.25 cm) at 2-3 lb/a (2-4 kg/ha) if drilled, double the rate if broadcast. Tolerates low soil fertility and persists better than white clover on low available P, acid soils.

Very leafy and high in feed value. Provides high quality summer forage with white clover, alfalfa, and fescue or phalaris grass species. Similar bloat hazard as white clover and alfalfa.

Persian Clover closeup inflorescence leaflets - Hollena Nori
Trifolium resupinatum L.

Late maturing annual legume with prostrate or semi-erect growth habit, high forage yield, and excellent regrowth following grazing or cutting.

Inflorescence is a flattened head with pink to purple flower petals having an upside down (resupinate) corolla. Seeds are tan to reddish-brown and very small. Stems are hollow, branching from the base. Leaves are trifoliolate with 0.4 to 1.2 inch (1-3 cm) long oval to oblong serrated leaflets. Stipules pointed with red veination. Tap rooted.   

There are two subspecies of Persian clover: majus and resupinatum. Majus is planted alone or in combination with oats or annual ryegrass in regions with >600 mm per year or in irrigated systems. Resupinatum is sown in dryland systems in regions with >450 mm per year as a winter forage crop in warmer areas or as a summer annual in more northern or higher elevation areas.

Suited to USDA Plant Hardiness Zones 7b-9b. It can survive cold winter temperatures and frost, but develops slowly at low temperatures. Moderate heat tolerance. Requires at least 450 mm of annual precipitation. Suited to loam to clay-loam soils with a pH between 5.5 and 9. Tolerates waterlogging and mild salinity.

Typically sown in autumn to be used during spring. Sowing rate is 6 to 8 lb/acre (5-10 kg/ha).

Forage is palatable with high digestibility and crude protein. Can produce bloat in cattle and photosensitivity in sheep grazing pure stands.

Red clover inflorescence - Hollander
Trifolium pratense L.

Short-lived, upright-growing perennial legume. Widely used in temperate regions for hay and silage in mixtures with grasses, for interseeding pastures, soil improvement, and as pollen and nectar source for bumblebees.   

Inflorescence is a spherical head composed of scores of rose-purple to magenta flowers. Pubescent stems are mostly upright with lower branching. Palmately trifoliolate leaves have oblong leaflets with crescent-shaped watermarks. Large stipules have green or red veining. Short taproots replaced by secondary roots after first year. Seeds are mitten-shaped, yellow to dark purple, about the size of alfalfa.

Extensively grown in the humid region of North America; USDA Plant Hardiness zones 4-8. Requires 25-40 inches (635-1000 mm) of precipitation or irrigation.  Grows best in fertile, well-drained to somewhat poorly drained soils of high moisture-holding capacity. Tolerates strongly acid soils but maximum yields require near-neutral pH. Moderately sensitive to saline conditions. May often have vigorous seedling vigor.

Seed no deeper than ½ inch (1.25 cm). Harvest for hay at early bloom stage. Rotationally graze in pastures.

Highly palatable and digestible forage. Bloat hazard when >30% of pasture mixture.

Rose Clover inflorescence - Carol Witham - CalPhoto0563
Trifolium hirtum All.

Rose clover is a herbaceous, self-regenerating winter annual legume. It has a semi-erect growth habit similar to crimson clover, with somewhat later growth period in mid-spring. It is used as a pasture species often combined with sub clover and medics and for stabilizing degraded areas. Also used as a vineyard cover crop.

Inflorescence is a head with scores of lavender-colored flowers. Leaves are pubescent, with obovate, pale green leaflets, usually with pale crescents bordered by brownish-red lines. Stems are 3-24 inches (8-60 cm) and densely pubescent. Stipules have green veination and are rounded, coming to a point. It is more deeply rooted than other annual clovers, rooting to 6 feet (2 m). Seeds are cream colored, approximately 2 mm long with about 250,000 seeds/kg (114,000/lb).

There are several cultivars varying in their maturity, rainfall required, cold tolerance, and optimal soil conditions.

Rose clover is native to the Mediterranean region and thus is suitable for regions which have 16 to 30 inches (400 to 750 mm) of annual rainfall and summer-dry conditions. Suitable in USDA Plant Hardiness Zones 6b-10b). Best growth in well-drained, sandy loams through clay loam moderately-drained soils. pH suitability is strongly-acid to moderately-alkaline soils (pH = 5.0-8.3). Tolerates neutral sodic soils (3-5 dS/m) and short periods (3 days) of waterlogging.

Widely in California, central Oklahoma, and north-central Texas; growing areas too dry for sub clover and too acid for medics.

Drill seeds 0.2-0.4 inches (0.5-1.0 cm) deep in autumn, using 2.7-6.3 lb/a (3-7 kg/ha) in a mix with other legumes and/or perennial grasses. Use group C inoculant and lime pellet if sown into acid soil or mixed with fertilizer.

Tolerates close grazing, but needs careful spring management to prevent overgrazing which will reduce seed production. Superphosphate and sulfur fertilizers should be applied every two to three years.

Produces high quality forage suitable for grazing, hay, or silage. High seed coat impermeability. Few disease or insect pests. Can cause bloat in cattle on pure legume stands. Negligible amounts of estrogen (no infertility issues detected in sheep).

Strawberry clover inflorescence leaf stipule - Ann Dennis
Trifolium fragiferum L.

Low-growing perennial legume with growth habit similar to that of white clover. Used for pasture and in mixtures with grass for hay and silage.

Inflorescence is sphere-shaped, borne on long stalks. Flower head is 10-12 mm in diameter, slightly smaller than white clover head with many small white or pink flowers with a base covered with shining white hairs. Fertilized flowers inflate to enclose the ripening seed, turning paper-like in color and texture. When mature, the inflorescence looks more like a dried raspberry than the strawberry after which it is named. Stems are semi-erect, glabrous, long, and thin. Palmately trifoliolate leaves with slender, spear-shaped leaflets; veining is close together and highly branched. Hairs on petioles and underside of leaflets. Stipules are glabrous, not toothed, with prominent veins. Deep tap root system. Seed pods are small, egg-shaped and contain 1 to 2 seed. Seeds are heart-shaped, light yellow to light brown with dark brown flecks.

Survives a wide range of temperatures during the growing season; USDA Plant Hardiness zones 4a-9b. Best production requires 25-40 inches (635-1000 mm) of precipitation or irrigation, but can survive in 18 inch (460 mm) rainfall zones.

Grows in waterlogged, well-drained through poorly drained, saline and alkaline soils. High flooding tolerance (7-30 days); can survive up to 3 months of moving water immersion. Tolerance is strongly acid to moderately alkaline soils (pH 5.1-8.4) and high salinity.

Poor seedling vigor makes it slow to establish. Once established, it will persist under heavy grazing pressure better than white clover. Seed no deeper than ½ inch (1.25 cm) at 0.5-1.0 lb/a (0.5-1 kg/ha) in mixtures with saline-tolerant grass species. Double the rate for broadcast seedings.

Tolerant of rotational or set-stocking and heavy grazing pressure once strong stolons have developed. A 2-4 inch (4-10 cm) canopy height reduces shading by grasses and improves clover persistence.

With adequate moisture, produces high quality summer forage. Can cause bloat in ruminants and increase urinary calculi in sheep.

Subterranean clover flowers leaf stipule - Holllander
Trifolium subterraneum L.

Winter annual reseeding forage legume. Important annual pasture legume in mixtures with perennial ryegrass or tall fescue for spring and early summer forage. Extensively planted on summer-dry hill-land pastures in western Oregon and northern California and for late winter and early spring forage in the southeastern USA.

Inflorescence is composed of three or four white florets. Corolla (petal) is usually white; calyx (sepal) color varies with cultivar, often red banded. Buries its seed pods before the onset of summer drought, hence its name. Pubescent, prostrate runners (stems). Palmately trifoliolate pubescent leaves with heart-shaped leaflets displaying cultivar-specific markings. Stipules green or red veining. Short tap- and lateral roots. Seeds are about 10 times heavier than white clover seeds and vary in color and weight with sub-species and cultivar; subspecies yannicum seeds are cream-colored, subterraneum and brachycalcycinum are black.

Suitable for coastal hills and pastures west of the Cascade Mountains in Oregon and California and coastal mid-Atlantic and Southeast US in USDA Plant Hardiness zones 7 and greater. Early flowering cultivars suited to low rainfall areas (less than 20 inches, 500 mm); later flowering cultivars suited to higher rainfall (greater than 30 inches, 700 mm). Grows best in moderately to well-drained loamy to clay-loamy soils that are moist through late spring. Tolerates strongly acid to medium alkaline soils (pH 5.1-8.4).

Weed control is essential for successful establishment since sub clover is a poor competitor and sensitive to shading. Prepare hill slopes by hard grazing. Drill seed to a depth of at least ½ inch (>10 mm). Seed alone at 8-9 lb/a (10 kg/ha) or at the same rate with low grass rates.

Graze lightly during the first spring flowering of newly established stands. During late autumn graze hard to remove dead grass.

Highly palatable and digestible forage in late winter and spring. Select low estrogen-containing cultivars to avoid livestock breeding problems.

White clover inflorescence and leaves - Hollander
Trifolium repens L.

Short-lived perennial forage legume.

Used in humid regions and irrigated grass-legume pastures worldwide. Large (Ladino) types also used for mixed grass-legume hay and silage. Shorter types are used as a cover crop, growing rapidly and spreading quickly via stolons; frequently used in orchards and vineyards as a cover crop, and to provide pollen and nectar for pollinators.

Inflorescence is a spherical head with 20-100 white to pinkish florets. Palmately trifoliolate leaves on long, glabrous petioles. Leaflets are oblong to wedge-shaped, with serrated margins, usually with a v-shaped water mark. Stipules are membranous. Most roots are found within the top 6 inches (15 cm) of soil. A short taproot develops after germination and is replaced by adventitious roots that develop at stolon nodes. Seeds are small, heart-shaped, smooth, and a yellowish to reddish color.

Suited to humid, temperate climate regions. Cold-tolerant but with low heat and drought tolerance. Requires 25-40 inches (635-1000 mm) of precipitation or irrigation.

Thrives on well to poorly drained soils. Tolerates long cool-weather flooding and acid to moderately alkaline soil conditions; best suited to pH 5.8-7.5. Moderately sensitive to salinity.

Seed no deeper than ½ inch (1.25 cm) at 2-3 lb/a (2.2-3.4 kg/ha) if drilled, double the rate for broadcast, the 2/3 rate for interseeding and in mixtures with grasses.

Requires good soil P and K status. Maintain clover stand by grazing grasses to avoid shading prostrate clover growth.

High in protein and digestibility; produces excellent forage quality. High bloat potential when grown alone or >30% of pasture mixture. Susceptible to slug damage.