How to Get Rid of Ruellia

Ruellia tweediana, also known as Mexican petunia, is a wildflower that is considered weedy and invasive in certain areas of the United States. It is officially classified as a Category 1 invasive species in the state of Florida. Ruellia's seeds germinate readily in nature, especially near bogs and other wetlands. Because of its extensive root system, ruellia is challenging to control and hand pulling a large amount of it nearly impossible. The best way to get rid of ruellia is with a poison ivy killer containing Triclopyr triethylamine salt or an herbicide containing glyphosate as its active ingredient.

Things You'll Need

• Herbicide

Instructions

1. Wait to apply the herbicide until you are sure that there will be no rainfall within 24 hours of application.

2. Spray the entire ruellia plant with the herbicide; ensure that both sides of the leaves and stems are covered but stop spraying before the product runs off the plant. The ruellia plant should die back to the soil within two months.

3. Reapply the herbicide if new growth appears. Apply it in the same manner as the initial application. According to specialists with the University of Florida IFAS Extension, this second application kills all remaining ruellia within two months.

Tips & Warnings

• All of the herbicides listed for control of Ruellia come in pre-mixed formulas, in applicator bottles, available at nurseries, hardware and home improvement stores, according to the experts at University of Florida Extension.

• To avoid damage to ornamental plants nearby due to herbicide drift, cover them with a tarp during the application.

References

• University of Florida IFAS Extension; Natural Area Weeds: Mexican Petunia (Ruellia Tweediana); Karen V. S. Hupp; December 2009