By Don Ball
Annual lespedeza was introduced into the United States from China, Japan and Korea in the mid-1800s. In these oriental countries, native stands of this plant are sometimes grazed or harvested for hay, but it is rarely planted. Interestingly, the plant seems to be even more ideally suited to climatic conditions in the Southern U.S. than in its area of origin.
Annual lespedeza is a warm-season annual legume that germinates in the spring, makes its growth during summer, then makes seed and dies in autumn. Dry matter yields are modest (only about 1 to 2 tons of dry matter per acre), but the forage quality is excellent. It is surprisingly tolerant of infertile and/or acid soils; it is a good reseeder and it does not cause bloat in livestock. It is also a good wildlife plant. Quail are particularly fond of the seed.
For many years, two species of annual lespedeza have been commonly grown in the U.S. Korean lespedeza, of which there are several varieties, matures seed in early autumn and is best suited for the upper South and lower Midwest. Striate lespedeza (of which ‘Kobe’ and ‘Marion’ are improved varieties) is more disease resistant, persists longer in autumn and has generally been the preferred annual lespedeza in Alabama.
Annual lespedeza is so well adapted to our climate it can be found in well-drained pastures, lawns and other areas throughout Alabama, but especially in about the northern half of the state. It seems to be a species we have largely forgotten about, as relatively little of it has been planted on Alabama farms in recent years. However, it may be time to take another look at it. Now that we know about the endophytic fungus that infects most of our tall fescue in Alabama, we need to find companion plants to grow with toxic infected fescue to reduce fescue toxicity problems in livestock. Also, since nitrogen prices have soared in recent years, it makes sense to grow forage legumes anywhere we can.
Annual lespedeza can be used for either pasture or hay, but is much more commonly used in pastures. It fits in best as a companion to tall fescue in pastures in North Alabama. Part of the reason for this is the summer growth of annual lespedeza complements the growth of tall fescue, which is not very productive in summer. A strong argument can be made that white clover is a better companion legume to tall fescue than annual lespedeza in many areas, but in places in which clover is unlikely to perform well (i.e. poor soil, slightly acid soil, droughty hills) annual lespedeza is a better choice.
Auburn University recommendations are to broadcast plant 25-35 lbs. of annual lespedeza seed per acre in February or March. The seed can be covered with 1/4 to 1/2 inch of soil, but will often become established without being covered if adequate moisture is present and pastures have been grazed closely. If the plants are not grazed so closely they are unable to make seed, annual lespedeza normally is a dependable reseeder.
High fertilization of a grass/annual lespedeza pasture with nitrogen will reduce lespedeza growth due to grass competition. Therefore, annual lespedeza is a particularly good choice of companion species for tall fescue in fields that will not be highly fertilized. Light grazing will allow some seed production for natural reseeding. Hayfields should be cut when the lespedeza reaches the early bloom stage.
As is the case with other forage species, annual lespedeza isn’t for every livestock producer or for every farm. However, the plant offers some valuable attributes and can be of great benefit in certain situations. It has the potential of being an important piece of the puzzle when a cattleman is trying to fit together a good forage program in North Alabama.
Don Ball is an Extension Forage Crop Agronomist with Auburn University.