Proc. Fla. State Hort. Soc. 117:289-290. 2004.


               ROBERT E. ROUSE1 AND FRITZ ROKA                                plies, perennial peanut is long-lived and does not require
                     University of Florida, IFAS                              replanting once established. It is well adapted to drought and
          Southwest Florida Research and Education Center                     the infertile sands in Florida. It is a legume that, in association
                     2686 State Road 29 North                                 with Rhizobium, fixes atmospheric N. This means that it re-
                    Immokalee, FL 34142-9515                                  quires no applied external nitrogen source (Beltranena et al.,
                                                                              1981). Phosphorus applications may be unnecessary in Flori-
                     ELAN M. MIAVITZ-BROWN                                    da sands rich in P. It is highly resistant to plant and soil pests.
                    Collier County Extension Service
                        14700 Immokalee Road                                                       Growing Environment
                       Naples, FL 34120-1468
                                                                                  Rhizomal perennial peanut grows best in full sun and will
Additional index words. Arachis glabrata, living mulch, drought               persist in partial shade after once established. Perennial pea-
tolerant, xeriscape                                                           nut will not thrive in full shade and will not normally spread
                                                                              under trees or other shade areas. Because rhizomes are un-
                                                                              derground stems perennial peanut does not spread over con-
Abstract. Rhizomal perennial peanut (Arachis glabrata, Benth)
originated in tropical South America and is adapted to sub-                   crete or paved areas. Perennial peanut is easily contained by
tropical and warm temperate climates. Perennial peanut was                    use of certain herbicides.
first introduced to the USA from Brazil in 1936 and has recently
shown promise as an ornamental groundcover due to its high                                            Planting Material
resistance to drought, nematodes, insects, diseases, and its
minimal fertilizer needs. Cultivars ‘Ecoturf’ and ‘Arblick’ are                   Cultivars. ‘Ecoturf’ and ‘Arblick’ are available cultivars for
available cultivars for landscape use. The cultivar ‘Florigraze’              landscape use. Both ‘Ecoturf’ and ‘Arblick’ were selected for
released for use in pastures also appears to be suitable for                  landscape application, due to their lower growth habit and
landscape use. Several systems can be used for planting pe-                   profuse flowering. Planting material for ‘Ecoturf’ and ‘Ar-
rennial peanut in a landscape setting. Plants can be estab-
                                                                              blick’ is available in limited supply. ‘Florigraze’ was released
lished from solid set sod, sod strips, sod plugs, or from plants
grown in nursery containers. Comparison of cost when plant-                   in 1978 for use in pastures and has been used recently in cit-
ing solid set sod and containers on 12 to 18-inch centers found               rus groves and along roadways. ‘Florigraze’ also appears to be
solid set sod to be advantageous. Sod provides instant 100%                   suitable for urban landscape use along landscape berms, ca-
groundcover. Planting strips, plugs, and containers require up                nal banks, and roadways, and has found favor in some lawn
to two years to achieve 100% ground cover.                                    landscapes and golf courses.
                                                                                  Source. Perennial peanut is propagated vegetatively using
    Rhizomal perennial peanut is not new, but has recently                    rhizomes (modified underground stems) that concentrate in a
shown promise as an ornamental ground cover. Perennial                        1.5 to 3.0-inch thick mat, just below the soil surface. Cut sod,
peanut was introduced into the USA from Brazil in 1936                        rolled mats of sod, and nursery containers are available forms
(French and Prine, 1991) and since that time no insect, dis-                  in which perennial peanut are available for landscape planting.
ease, or nematode pests have been identified that cause eco-
nomic loss (French et al., 1993). It is not only beneficial to the                                   Planting Methods
environment since it requires no supplemental nitrogen or
phosphorous fertilization, and remains green requiring less                        The most desirable system of planting perennial peanut
water to keep than traditional ground covers. It also has yel-                groundcover in the landscape is solid set sod because it pro-
low flowers that add a benefit of being aesthetically pleasing                vides complete and instantaneous cover. However, several sys-
and can withstand walking traffic.                                            tems can be used for planting perennial peanut in a
    The perennial peanut (Arachis glabrata, Benth) evolved                    landscape setting. In addition to planting solid set sod, sod
under tropical conditions and is adapted to subtropical and                   strips, sod plugs, and usually one-gallon nursery containers
warm temperate climates similar to Florida. In the northern                   can be used. With these methods the planting density can be
hemisphere, this would include locations below 32° north lat-                 adjusted to reduce the time required for the plants to fill in
itude that have a long, warm growing season. Perennial pea-                   between planted material. Strip planting can be done using
nut is used as a forage legume for grazing (Saldivar et al.,                  sod strips as they are delivered or cut into narrower strips, but
1992), as a high-value hay crop, and as a cover crop in citrus                strips should not be less than eight to ten inch widths. Rows
grove row middles (Mullahey et al., 1994; Rouse and Mulla-                    could be 12 but not more than 18 inches apart. Sod plugs can
hey, 1997; Rouse et al., 2001). A select number of cultivars are              be cut from the delivered sod pieces into smaller squares and
available for use in home landscapes in south Florida.                        planted in a checkerboard layout. Sod plugs should be plant-
    Rhizomal perennial peanut has several potential advan-                    ed on centers no more than 12 to 18 inches apart. Peanut in
tages over grass in the managed landscape. As its name im-                    one-gallon nursery containers can be planted the same as sod
                                                                              plugs. One additional method is to obtain the loose rhizomes
                                                                              and plant them directly in the soil. This can be done with one
    This research was supported by the Florida Agricultural Experiment Sta-
tion, and approved for publication as Journal Series No. N-02550.             of two methods. One is to spread the rhizomes in a solid layer
    1Corresponding author.                                                    and cover with a layer of soil. The soil should then be covered

Proc. Fla. State Hort. Soc. 117: 2004.                                                                                                       289
with one to two inches of composted mulch to help maintain         well as a few other select broadleaved weeds. Herbicide recom-
soil moisture and reduce weed growth. A second direct rhi-         mendations in this report are contingent upon their contin-
zome planting method is to place the rhizomes in furrows and       ued registration by the Environmental Protection Agency. If a
cover with soil and mulch. If this is tried the rhizomes should    registration is canceled, the herbicide will no longer be recom-
not be placed more than 1.5 to 2.0 inches deep. The distance       mended. The use of product trade names does not constitute
between planted rows of rhizome material is best kept to no        a guarantee or warranty of the products named and does not
more than 12 to 18 inches and coverage time (fill-in) usually      signify approval to the exclusion of similar products.
will increase as distance between rows decreases. Planting
should be followed by a packing-roller that leaves the ground                                        Mowing
leveled, preserves soil moisture and achieves good rhizome to
soil contact. Irrigation should follow planting and roller pack-       Appearance will be enhanced with mowing although it is
ing. It was observed that rhizomes can take up to two growing      not required with the lower growing varieties like ‘Ecoturf’.
seasons to fill in while sod pieces placed corner to corner pro-   Mowing stimulates new vegetative shoots making a thick can-
vide an instantaneous ground cover. Planting strips and plugs      opy and encourages flowering. Mowing at three to four inch-
take less time to fill than rhizomes.                              es every three to four weeks is usually adequate.
                                                                       In conclusion, perennial peanut is a suitable landscape
                           Irrigation                              groundcover in central and south Florida. It is drought toler-
                                                                   ant, requires no supplemental N or P, and is environmentally
    Although once established, rhizomal perennial peanut           friendly. Perennial peanut may suppress weed growth, reduce
does not require irrigation for survival (French et al., 1993),    nutrient leaching and add nitrogen and organic matter to the
irrigation is required following planting during establish-        soil. As with other cover crops, perennial peanut has the po-
ment. Irrigation may be required during dry periods in early       tential to compete with trees for water and nitrogen if allowed
Spring and Autumn to maintain a thick canopy cover. Soil-          to grow around the base of plants.
plant moisture status should be carefully monitored during               Perennial peanut isn’t invasive. Since its introduction, it
dry months. Water, fertilizer and weed control are all impor-      has not spread into natural areas or become a nuisance plant
tant inputs that can maximize plant density during the first       in unimproved properties. Rhizomal perennial peanut does
growing season.                                                    not reproduce by seed; therefore, it can’t be carried by birds
                                                                   or wildlife.
                        Weed Control
                                                                                                Literature Cited
     Weed control is the major management practice during
                                                                   Beltranena, R., J. Breman, and G. M. Prine. 1981. Yield and quality of Flori-
establishment and for continued management. Eliminating               graze rhizoma peanut (Arachis glabrata Benth.) as affected by cutting
tall weeds competing for sunlight ensures greater survival            height and frequency. Soil Crop Sci. Soc. Fla. Proc. 40:153-156.
during the dry months prior to summer rainfall and allows          French, E.C., and G.M. Prine. 1991. Perennial peanut: An alternative forage
the plants to grow and spread more rapidly (Rouse and Mul-            of growing importance. Fla. Coop. Ext. Ser. Agron. Facts SS-AGR-39.
lahey, 1997). Keeping the perennial peanut canopy clear for        French, E. C., G. M. Prine, W. R. Ocumpaugh, and R. W. Rice. 1993. Regional
                                                                      experience with forage Arachis in the United States, p. 167-184. In P. C.
maximum sunlight penetration is critical to proper develop-           Kerridge and B. Hardy (eds.), Biology and Agronomy of Forage Arachis.
ment and speeds establishment of the peanut cover crop.               CIAT, Cali, Columbia. Chapter 15.
     Mowing has been found to be the least expensive weed          Mullahey, J. J., R. E. Rouse, and E. C. French. 1994. Perennial peanut in citrus
control method. Mow the peanut whenever necessary to re-              groves—an environmentally sustainable agricultural system. Proc. Sec-
                                                                      ond Conference of Environmentally Sound Agriculture, Orlando, Fla.
duce weeds and mow at a level just above the foliage of the           2:479-483 (Published by Am. Soc. Ag. Engineers).
peanut during establishment and at three to four inches for        Rouse, R. E. and J. J. Mullahey 1997. Perennial peanut ground cover in citrus
continued maintenance. Mowing should be done whenever                 orchard row middles and discussion of potential environmental benefits.
weeds are shading the peanut. Other weed control methods              Fla. State Hort. Soc. 110:79-82.
do not appear to reduce establishment time (Rouse and Mul-         Rouse, R. E., R. M. Muchovej, and J. J. Mullahey. 2001. Guide to using peren-
                                                                      nial peanut as a cover crop in citrus. Fla. Coop. Ext. Serv. Factsheet, HS-
lahey, 1997). For grassy weeds such as crabgrass, bermudagrass        805.
and bahiagrass, Fusilade®, Poast®, Select®, and Prism® her-        Saldivar, A. J., W. R. Ocumpaugh, R. R. Gildersleeve, and G. M. Prine. 1992.
bicides are cleared for use during establishment. Basagran®           Growth analysis of ‘Florigraze’ Rhizoma peanut: Shoot and rhizome dry
and Cadre DG® are effective for control of yellow nutsedge as         matter production. Agron. J. 84:444-449.

290                                                                                                   Proc. Fla. State Hort. Soc. 117: 2004.

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