Keys Homes
Sunday, July 14, 2013
Love at first sight occurs with the perennial peanut groundcover

By ROBIN ROBINSON The Key West Garden Club

Imagine you have met your soul mate. Everything is right. You grow together in perfect, healthy harmony. No bad habits or annoying relatives. Every day is sunny. There are no worries about nasty nematodes or nettling neighbors.

That is what you get when you plant perennial peanut (Arachis glabrata), a nitrogen-fixing groundcover first introduced to South Florida from Brazil in the 30s. What a gift it was! The legume has no insect pests, diseases or nematodes. Once established, it is drought tolerant, loves full hot sun and high humidity. It is fond of well-drained soil that is full of phosphorous. It can be mowed or not. It pops back up after being walked upon. It is not invasive as it grows from rhizomes and produces few seeds so birds do not transport it.

It's four, oval, dark-green leaflets withstand salt spray, salt drift and even short term salt-water flooding.

Perennial peanut grows to 10-inches tall. If it is mowed down to 4 inches, it will respond by putting out new growth that increases the thickness of the carpet. Also, mowing destroys any weeds that invade the planted area. Before mowing, pick the bountiful, yellow pea flowers to put in a salad.

This hearty groundcover is planted along roadsides and median strips, in yards and golf courses, berms and especially wherever there is runoff. Citrus orchards enjoy its nitrogen fixing properties. It would look good in front of hotel entryways and take much less water and care than the water-hogging impatience or other northern plants.

Perennial peanut has so many great characteristics that it is hard to understand why it is not planted everywhere in this sub-tropical climate. Pity the poor love-struck northerners, as it will not grow where it hard freezes, but it can withstand a light frost growing back from its rhizomes.

Institute of Food and Agricultural Sciences studied the peanuts to increase their genetic diversity creating 40 different cultivars. In recent years, it began releasing them to commercial sod producers and into the public domain.

Two cultivars, Ecoturf and Arblick, were developed by the University of Florida's ISAF and are recommended for their low growth habit and profuse flowering.

A third cultivar, Florgraze is recommended when the perennial peanut is used as fodder for horses, dairy and beef cows, goats, and sheep. Since it is so high in nutritional value, mature horses will gain weight, dairy cows produce more milk and beef cattle put on weight faster.

To plant perennial peanut, purchase rolls of damp sod filled with the rhizomes. They should be unrolled and planted immediately as they do poorly if they dry out. They must be irrigated until they are firmly rooted. They can be strip-planted leaving 12-18 inches in between strips. Plugs also can be used, but take longer to cover a large area. Each plug will eventually spread over a two-foot radius.

Perennial peanut will cost more than St. Augustine grass initially, but within four years will pay for itself with reduced water and fertilizer charges. St. Augustine grass needs 174 pounds of nitrogen fertilizer an acre where perennial peanut produces its own nitrogen. It is economical because it is long-lived so it does not require replacement.

In Key West, check out Shirley Freeman's front lawn on Eaton Street to see a huge sunny expanse of water-saving perennial peanut.


The Key West Garden Club welcomes volunteers to work on the historical fort, pull weeds, propagate plants and play in the sandy soil at the West Martello Tower from 9 a.m. to noon on Mondays.

Key West Master Gardener Robin Robinson was a columnist for the Chicago Daily News and syndicated with Princeton Features. Her books "Plants of Paradise" and "Roots Rocks and Rain: Native Trees of the Florida Keys," can be found at the Garden Club and on This column is part of a series developed by the Key West Garden Club. For more information visit

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