Trifolium incarnatum L.
Trifolium incarnatum L. var. elatius Gibelli & Belli
Crimson clover is native to the Mediterranean region, introduced into the U.S. during the 1800's. It is well suited for the southern states from Virginia to eastern Texas and in Oregon where seed production is the objective. It is easy to establish since it has large seeds and good seedling vigor. Since it is a winter annual, it is most often used for overseeding warm-season perennial grasses for winter and spring grazing. It provides an early maturing forage and is adaptable for a wide range of soils which many legumes are not. It can tolerate a wide range of pH (5-8) but is not tolerant of poor drainage. It likes more than 30 inches of rainfall.
Image Gallery: The OSU Forage Information System contains an Image Gallery that includes Crimson Clover photographs and drawings useful in identification. The URL for the gallery is: http://forages.oregonstate.edu/main.php?PageID=241The direct URL for Crimson Clover is: http://forages.oregonstate.edu/main.php?PageID=178&SpecID=40
Inflorescence: Crimson clover inflorescence image.
Flower: Crimson clover flower image.
Seed: Yellow, spherical Crimson clover seed image.
Leaf: Crimson clover leaves image.
Stipules: Crimson clover node image.
Crimson clover generally is planted in the fall. During the fall and winter, it grows slowly, the leaves forming a low rosette clump. It puts on most of its growth in spring, when tall, erect flower stems emerge and develop leaves at numerous nodes. Flowering is induced when day length exceeds 12 hours. Crimson clover reseeds well if allowed to mature and if sufficient moisture is available. Many varieties have high proportions of hard seed. Crimson clover has cool-season (C3) physiology.
Short, rounded, hairy stipules; Inflorescence: long, conical head with crimson flowers
Crimson clover needs moist soil to germinate, and seedlings do not tolerate drought. It can become a weed in following crop.
Crimson clover does not survive extreme heat or cold and grows best in cool, humid weather. It cannot endure much drought and does not do well on poorly drained soils. Moist soil is essential for germination and establishment. Crimson clover is moderately shade-tolerant.
Soils: Crimson clover is adapted to soils of low fertility and has an intermediate lime requirement. It can tolerate pH ranging from 4.8-8.2 but does better at pH closer to 6.5. It grows on a wide range of soil types as long as drainage is good; however muck or extremely acid soils do not support good growth.
Grazing Management: When grown in combination with winter annual grasses, care should be taken to prevent excessive grass growth from shading out the clover plants, especially early in the growing season. Increasing the stocking rate or allowing animals access to a pasture earlier than had been planned may be necessary to accomplish this. Ideally, crimson clover should not be grazed until the plants are 4 to 6 inches tall. Turning livestock into a pasture when plants are small and the soil is moist can result in damage to the stand by hoof action, especially on prepared seedbeds. Crimson clover should not be grazed closer than around 3 inches. Given the potential problems associated with either undergrazing or overgrazing, careful observation of pasture stands followed by appropriate grazing management is advisable. Autumn growth of any overseeded winter annual forage, including crimson clover, is considerably lower than when planted on a prepared seedbed in early autumn. As a result, the total production from overseeded stands is less, and the beginning of grazing will be delayed by two months or more.
Pests: Diseases: Susceptible to crown and stem rot, fusarium wilt disease, sooty blotch, leaf and stem spot, and viruses.
Pests: Insects: Problems with fall armyworms, cutworms, the yellow-striped armyworm, the Hawaiian beet webworm, and bean beetles.
Common varieties of crimson clover germinate rapidly with a minimum of hard seed. The varieties 'Dixie,' 'Autauga,' 'Auburn,' 'Chief,' and 'Kentucky' were developed to self-reseed and have a high proportion of hard seed. They are most apropriate for fall planting when irrigation will not be used. 'Common Dixie' crimson clover is widely available in Oregon.
Vendor section not to be used in "Beneficial Species White Papers."
Forage Information System Database of Vendors (type in crimson clover in the search text box)
Best stand establishment is obtained when crimson clover is drilled 1/2 to 3/4 inch deep into a firm, well-prepared seedbed. Alternative seeding methods that can reduce seedbed preparation but require higher seeding rates are: drill into a rough seedbed prepared by disking, or broadcast over a rough or smooth seedbed and then disk lightly to cover seed. If the soil is dry, irrigate or plant before a fall rain. Plant crimson clover early enough so that the stand is established at least 6 weeks before the first frost to prevent frost heaving damage and winter-kill.
Normally, 20 to 30 pounds of seed per acre (22.5-34 kg/ha) is recommended when crimson clover is planted in pure stands. A thick stand, such as should be obtained with 30 pounds of seed/acre (34 kg/ha), results in more autumn and winter growth. If planted with small grain and/or ryegrass, 15 to 20 pounds of crimson clover seed/acre (17-22.5 kg/ha) should be adequate. To avoid excessive competition for the clover, seeding rates of small grain and/or ryegrass in mixtures should be no more than 90 and 15 to 20 pounds/acre (17-22.5 kg/ha), respectively.
Best stand establishment is obtained when crimson clover is drilled 1/2 to 3/4 inch deep into a firm, well-prepared seedbed.
Phosphorus, potassium, and lime applications made in autumn according to soil test recommendations should be adequate to take crimson clover or a crimson clover/winter annual grass mixture through the spring growth period. In addition to whatever level of N may have been applied in autumn or winter, an additional application of around 60 pounds of N/acre is usually made to crimson clover/grass mixtures in late winter.
Pasture with warm-season grasses; hay; silage
Roadside stabilization and beautification
David B. Hannaway and Daniel Myers, Oregon State University
4 August 2004
13 September 2004