Perennial peanut does well in the lower regions of the South (Zones 8b to 11), extending from southeast Texas and around the coastal areas to southeast North Carolina. They are particularly well suited to the hot climate and sandy soils found in most of the region. Since their introduction in 1936, these Brazilian natives have performed admirably. Tolerance of salt spray, salt drift, and temporary flooding by salt water makes it even more suitable in areas where salt-laden breezes sweep in constantly from the Gulf of Mexico.
Perennial peanut is frequently used as an ornamental groundcover. During the summer, a thick mat about six inches high out competes most weeds and undesirable plants and adds a sprinkling of attractive, yellow flowers. In places with winter frosts, the tops get killed to the ground. However, the plants re-emerge the following spring provided the rhizomes are not frozen. If a green cover is desired during the winter months in the northern portions of its range, overseeding with annual ryegrass will achieve the desired effect.
Growing Perennial Peanut
Best performance will result if perennial peanuts are planted in full sun, but they can also grow in partial shade. They require very well-drained soil, and grow well in soil ranging from a pH of 5.0 to 7.5. The addition of organic matter can lighten heavy clay soils and improve drainage. Weed control is important during the establishment period. Afterwards, the thick mat of foliage out-competes all but the toughest and most persistent weeds.
Very little maintenance is required once perennial peanuts become established. Like other legumes, they fix their own nitrogen. Because plants need other nutrients, the addition of a fertilizer with no nitrogen, and perhaps no phosphorus since it is often plentiful in most of the region, but with potassium and magnesium, would encourage best growth. Resistance to drought, nematodes, and pathogens means that little must be spent on water or on controlling pests. No invasive tendencies have been noted, probably because no seeds are produced that can be transported by birds or other wildlife.
Perennial peanuts can be mowed every three to four weeks to a height of three to four inches, if desired. Doing so will stimulate flowering and make the groundcover even and more turflike. Edging may be necessary to keep the plants in bounds.
Propagation is by division of the rhizomes or by rooting tip cuttings while plants are actively growing.
Kinds of Peanuts
The two cultivars most frequently used for ornamental groundcovers are ‘Arblick' and ‘Ecoturf'. Other cultivars, such as ‘Florigraze' and ‘Arbrook' are taller growing and are usually grown as forage crops. The hay produced is similar in quality to alfalfa. Although the protein content is a bit lower, the energy content is higher.
Other species of peanuts are grown for various purposes. In addition to Arachis glabrata and A. hypogaea, over 100 additional species and varieties are listed on the GRIN (Government Resources Information Network) website. All share some common characteristics but are different enough to be considered different species.
Other Uses for Perennial Peanut
Not only is perennial peanut an excellent groundcover for home landscapes; it is also ideal for road medians, driveways and parking lot islands. Golf courses, berms where mowing would be difficult, septic tank mounds, and canal banks are all potential candidates for these adaptable and easy-to-grow plants. They work well as a buffer to waterways to prevent runoff of nutrient laden water.
At a Glance
Scientific name: Arachis glabrata
Say: a-RAK-is GLAB-rah-tuh
Common names: Perennial peanut, ornamental peanut
Family: Fabaceae (Pea family)
Origin: South America
Light: Full sun to partial shade
Water use zone: Low to moderate
Size: 6 inches
Soil: Well-drained; pH 5.0-7.5
Salt tolerance: Excellent
Thanks to Melody for the image of common peanut.