White Clover
White clover, a true perennial, is the most widely-grown clover in the United States. Where adapted, individual plants often live for several years. Ladino varieties of white clover are usually most productive, but generally do not reseed well. Intermediate white clover types are better reseeders and more persistent, but usually are less productive. White clover is tolerant of close grazing, which makes it a good choice for many pastures, but it is not well-suited for hay situations. Though widely adapted, it is best suited to soils which have good moisture-holding ability.
Red Clover
Red clover has excellent seedling vigor and larger seed than white clover, which facilitates drilling it into existing grass pastures. In many areas red clover plants can live for 2 years (and occasionally longer), but in the lower South it often acts as an annual. In areas where it is well adapted, it is the best-yielding clover species. It is often grazed, but is also well suited for use in hay situations. It is not tolerant of continuous close defoliation; rotational stocking is best. Red clover requires good soil moisture, but is not as tolerant of wet conditions as white clover.
ANNUALS
Arrowleaf Clover
Arrowleaf clover is a productive annual that makes most of its growth in late spring. It produces a high percentage of hard seed, which favors reseeding. The seed can germinate at lower temperatures than most annuals. It is usually grown in pastures, but can also be cut for hay (one cutting only). Arrowleaf/grass mixtures should be grazed enough to prevent the clover seedlings from being shaded by the grass. Arrowleaf clover requires well-drained soil.
Ball Clover
This winter annual is sometimes mistaken for white clover, but the blooms are smaller and more rounded. Although it can be quite productive, ball clover has a shorter growing season and often yields less than other commonly grown annual clovers. It is a prolific seed producer even under high stocking rates, and a high percentage of the seed are hard seed. Thus, it is an excellent reseeder. The primary period of growth is early to mid-spring. Ball clover is best suited to heavy soils, but is surprisingly well adapted to fairly dry sites as well.
Berseem Clover
Berseem clover is an annual which bears a superficial resemblance to alfalfa. If planted in autumn, most growth occurs in mid-spring. Within 100 miles of the Gulf Coast it often produces more autumn and winter forage than any other clover, but because it does not have good cold tolerance, production declines as it is planted farther north. Rotational stocking is the best way to utilize berseem clover pastures. This clover does not reseed well due to a low level of hard seed production. Unlike most commonly grown annual clovers, berseem clover is quite tolerant of wet soils and also alkaline soils.
Crimson Clover
Crimson clover is a dependable, productive annual which has larger seed and better seedling vigor than most clovers. Crimson clover makes more growth during cool weather than most clovers and is the earliest-maturing commonly grown clover species. Thus, in addition to forage production situations, it is often used as a winter cover and/or green manure crop. The showy crimson-colored blooms can provide a spectacular show in early to mid-spring. This clover should be planted on well-drained soils.
Rose Clover
Rose clover has a growth habit similar to crimson clover, but has lavender-colored blooms and makes most of its growth in mid-spring. It is one of the most tolerant clovers to drought and low fertility conditions. The most hardy variety has similar winter hardiness to arrowleaf clover or crimson clover, but varieties often grown in western states are much less cold tolerant. Rose clover produces many hard seeds, and reseeding is often good. It is best suited to well-drained soils, and is most popular in certain low rainfall areas of central Oklahoma, north central Texas, and California.
Subterranean Clover
Subterranean clover is a dense, low-growing annual best suited to areas having mild winters. It makes most of its growth in mid-spring. Subterranean clover does not yield as well as arrowleaf clover, berseem clover, or crimson clover, but can produce seed under heavy grazing pressure. However, success in obtaining reseeded stands varies depending on environmental conditions at seed maturation. Subterranean clover is more tolerant of low fertility and shade than most clovers. It is best adapted to medium and heavy textured soils with good moisture-holding capacity.
Final Thoughts
A good way to determine the usefulness of various clovers in a given situation is to simply purchase some seed and make trial plantings. Small test plantings are inexpensive and can provide much insight that can help with species selection decisions in future years.
However, it is important to make certain that any such test plantings give the clovers a fair chance. The soil pH and fertility needs of the clovers should be met, the seed should be inoculated with good quality inoculum of the proper type, and the seed should be planted properly at the recommended time, rate, and depth.
Varieties within a clover species can vary considerably with regard to yield, disease resistance, winterhardiness, and other factors. Thus, once a decision has been made as to which clover species to plant, selection of the most suitable variety can mean the difference between good and poor results, University variety trial reports are the best sources of unbiased variety information.