Diligent care controls Florida betony

This past spring, as a 50th wedding anniversary present for my parents, we redid the landscape in the front of their home. The plant materials were old and doing poorly.

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The plant beds had a large number of weeds in them, and there was one weed that I dreaded seeing: Florida betony (Stachys floridana Shuttlew.)

Florida betony is one of the hardest weeds to control in ornamental beds and turf. In order to control this weed, I dug up the beds and raked and hand-picked the tubers, hoping for the best.

This past weekend, I was at my parents' house and the beds looked pretty good. There was some betony growing, but the number was very small compared to last year.

Florida betony is a member of the mint family. You can tell a plant that belongs to the mint family because they have square stems. Plants in the mint family are hard to control, because most of them spread by underground rhizomes.

In the case of Florida betony, the plant produces an underground rhizome that will have two- to three-inch tubers. The tubers look like the rattles on a rattlesnake. This is how it gets its common name: rattlesnake weed.

These tubers can store a large amount of energy, which allows the plant to regrow each year and after herbicide applications. The plant can regenerate from root pieces or portions of the tuber that is left in the ground.

Florida betony is a winter perennial. It will emerge in late September to early October and will go dormant when the weather gets hot in May.

The leaves of Florida betony are opposite each other and are long-stalked and lance-shaped with toothed margins.

The plant will grow all winter and in early spring, then produce flowers. The flowers can be white or pink with purple spots. The flowers have two lips on them. The upper lip is hooded, and the lower lip has three lobes.

These flowers produce seed that is viable, so Florida betony can be spread by seed.

Products to control Florida betony depend on where it is growing. In turf grass, products containing atrazine, 2,4- D, dicamba, or mecoprop provide good selective control.

Other herbicides have shown some control. University of Georgia research found that the following herbicides provided greater than 70 percent control two months after application: Monument (trifloxysulfuron), Manor (metsulfuron), Revolver, (foramsulfuron) and Speedzone (carfentrazone, 2,4-D ester, mecoprop, and dicamba). These herbicides are labeled only for turf grass and are not available to homeowners.

In ornamentals, dichlobenil (sold under the trade name Casoron) provides excellent control of Florida betony in some established woody ornamentals. Dichlobenil cannot be applied over every ornamental plant.

You will need to check the label to see where it can be used and on which plants.

Products containing the active ingredient glyphosate, such as Roundup, can be used to control this plant in ornamental beds if applied as a spray directly to the betony without contacting desirable plants.

If you are trying to establish a new bed that contains Florida betony, consider using glyphosate. Applying a 5 percent spray solution of glyphosate one week before cultivating the area will help reduce much of the betony population. Repeating the applications will eliminate survivors.

Maintaining a good four- to six-inch layer of pine bark or pine straw can eventually smother the betony.

In plant beds, betony will need to be hand-pulled. In areas that have a layer of mulch, the tubers of the betony will be growing in the mulch. Removing the mulch can remove a large amount of tubers.

Florida betony is a very hard weed to control, but it can be done by reacting when the plant first appears and staying on top of it.

Columbia County Extension Agent Charles Phillips can be reached at (706) 868-3413 or by e-mail at charlesp@uga.edu. The extension Web address is www.ugaextension.com/columbia.