Plant Common Name
The unusual and economically important peanut is a bushy or spreading tropical plant that may be grown as an annual or short-lived perennial crop. Technically a member of the bean family (Fabaceae), the peanut's origins stem from South America (Bolivia, Peru and adjoining countries) where they were grown and eaten by indigenous peoples. They have since become essential to life and cuisine in countries worldwide including Africa, Asia, The Pacific Islands and North America. Peanuts were introduced to the United States very early on in Colonial times and were initially used to feed livestock, particularly pigs. They did not gain popularity for food until the late nineteenth and early twentieth centuries. George Washington Carver's perfected recipe for peanut butter helped peanuts gain acceptance as an everyday American food.
There are several types/groups of peanuts that vary in fruit size, branching habit, yields and disease resistance, among other traits. These include Runner, Tennessee White and Red, Spanish, Valencia and Virginia Groups. Runner peanuts are a popular crop in the southern United States and have spreading plants that produce excellent peanuts ideal for roasting and peanut butter; Tennessee reds and whites are smaller and less productive than most modern peanuts and differ in skin color; Spanish peanuts are small but flavorful, high-yielding and disease resistant; Valencia are large and preferred for roasting; and Virginia are large and often sold in-shell.
Peanuts may have two habits; some form bushy clumps and others run and spread to form mats of foliage. The green leaves are compound and have four leaflets and the upright or creeping stems may be green or reddish. The stems set roots as they touch the ground. Clusters of sweet pea like flowers of yellow, sometimes with orange-red highlights, bloom along the plant's stems when weather is favorable. After pollination by insects, the flower stems lengthen and bury themselves underground. The peanut pods develop underground.
Harvest must be carefully timed. This is because the whole plants are pulled up upon harvest. If the pods are not perfectly ripe, the crop will be lost. If they are too ripe and plants too dry, the plants will come up while leaving the peanuts in the soil. On average they ripen between 80 and 150 days after planting, depending on the variety. Whole plants are lifted and placed on drying racks where they are typically dried for a few days before being taken to a "drying station" that forces warm air over the curing peanuts. Once fully dry they can be roasted, shelled and processed.
Peanuts grow best in full sun and sandy loam that allows for easy harvest. Well-drained soil also helps protect against the fungal diseases that plague peanuts. In addition to well rounded all-purpose fertilizer, peanuts need a good Calcium supply for good germination and fruit set.
Peanuts are a fun crop for children to grow, as long as allergies are not a problem. Sadly, peanut allergies are fairly prevalent and violent if present. It's hard for home gardeners to grow enough peanuts to make growing them worthwhile.
Peanut hulls make a valuable, sustainable mulch for garden beds if you can get them.