Among the roughly 70 species of phlox (Phlox spp.) most are low-growing or trailing plants, but some upright, shrub-form species reach several feet tall. Most grow in U.S. Department of Agriculture plant hardiness zones 2 through 10, but this varies among species. Phlox can sometimes be hand-pulled, but it's difficult to remove all the roots, particularly with creeping varieties, so a herbicide application can help completely remove the phlox.
Mix 2 2/3 ounces of herbicide with 1 gallon of water in a spray bottle or 1 gallon garden sprayer to make a 2 percent glyphosate solution. The regular formula of common glyphosate brands contains roughly 41 percent glyphosate, but check the label before mixing. Use a product with a surfactant so the herbicide coats foliage more easily.
- Among the roughly 70 species of phlox (Phlox spp.)
- Phlox can sometimes be hand-pulled, but it's difficult to remove all the roots, particularly with creeping varieties, so a herbicide application can help completely remove the phlox.
Use lopping shears to cut shrubs back to about 6 inches. Mow over shorter phlox with your lawn mower set at its highest setting.
Spray the phlox with the glyphosate solution to completely wet all parts of the phlox plants. The surfactant coats the plant and reduces runoff. Allow seven to 10 days for the herbicide to take effect and dry out the plants. The phlox should shrivel up and turn brown.
Spray any green parts that remain after 10 days with the herbicide. Wait until those plants die.
- Use lopping shears to cut shrubs back to about 6 inches.
- Allow seven to 10 days for the herbicide to take effect and dry out the plants.
Turn the dead plant material into the soil, using a garden hoe or rototiller. It will improve soil tilth and drainage. The plant matter decomposes in the soil, just as plant matter breaks down when added to a compost pile. Alternatively, you can break up the soil, rake up the dead phlox and add it to your compost pile or a green materials waste bin.
Monitor the area for new phlox growth and spray the new growth immediately with the herbicide solution. Repeat this process until the phlox no longer returns.
A 1-quart spray bottle works well for treating a few phlox plants. If you want to get rid of a large patch of phlox, a 1-gallon garden sprayer works best because it holds more herbicide and the spray nozzle can cover a wider area.
Check the product's label, as instructions vary by brand. Keep children and pets out of the area you've sprayed until the solution has dried. Wear gloves and protective eyewear when working with herbicides. Always wash your hands thoroughly after handling garden chemicals.