Controlling Florida Betony
The Extension office has received calls about a weed called Florida betony. It is also called wild artichoke or rattlesnake weed. This aggressive weed is happily growing in lawns and in ornamental beds.
Florida betony is a freely branched perennial with hairy square stems. Leaves are opposite, lance shaped and have toothed edges. Flowers are usually pink and resemble mint flowers. It has slender underground stems called rhizomes with segmented white tubers. The tubers are sometimes described as looking like a rattlesnake’s tail or a carrot. Once you see them it is hard to forget.
The Latinized English species name floridana refers to the fact that it was first named from a Florida collection. This species was thought to be restricted to Florida until the 1940s or 1950s. This weed occurs on wet sandy soils, lawns, roadsides and thickets from Virginia south to Texas.
This weed is a ‘winter’ perennial and is usually found in bare or thin areas of the lawn. Florida betony actively grows in the mid to late fall and spring months. Turf that contains Florida betony should be evaluated to promote vigorous growth of the grass species.
Control in the turfgrass with most postemergence broadleaf herbicides such as atrazine or MCPP (also called mecoprop) or clopyrilid plus triclopyr. Most products containing atrazine may be used on established lawns of St. Augustine and centipede. Apply in the fall to the emerged Florida betony followed with a second application in February. Do not apply atrazine containing products within the active root zone of desirable ornamental plants such as camellias, azaleas, or boxwoods.
Products containing MCPP can also be used to control Florida betony. Two products for the homeowner are Chickweed and Clover Control and Weed-B-Gon for Southern Lawns Formula II. The chickweed and clover product may be used on all warm season and cool season lawn grasses except St. Augustine grass. Weed-B-Gon for Southern Lawns Formula II may be applied to all warm and cool season turf grass. As with atrazine, these products should be applied to the leaves of Florida betony. If necessary, a second application eight weeks after the first may be needed for effective control. Do not exceed label rate recommendations. Read the label carefully for precautions pertaining to safe application to protect the turf, desired ornamentals, and the environment.
Few chemicals are labeled in woody ornamentals to control Florida betony. Control options include hand pulling and hoeing but all tubers must be completely removed. Dichlobenil is the chemical providing good control but it should be used in cool temperatures. It is a volatile herbicide that readily escapes as a gas under high air and soil temperatures. Several trade names are available that include precautions for use. Do not use it on fir, hemlock, Ilex crenata (Japanese Holly), Ilex rotunda or Ilex vomitoria (Youpon Holly). Do not use more than 6 pounds per acre on azalea, rhododendron, boxwood, holly, euonymus, forsythia, leucothoe, ivy, lilac, heather, or any planting less than one-year-old. Do not use in seedbeds, cutting, or transplant beds. Do not apply until 4 weeks after transplanting any plants.
Products containing the active ingredient glyphosate can also be used to control Florida betony. Apply directly to plants without contacting desired plants. No matter which methods you choose to kill this weed be patient. It will take at least two years to remove this hard to kill weed.
Always read the pesticide label and follow the directions exactly.