Things You\’ll Need
Russian sage (Perovskia atriplicifolia) is a semi-woody groundcover that, from summer until fall, produces small lavender blooms that grow along 3- to 5-feet tall flower stalks. They are hardy in U.S. Department of Agriculture zones 5 to 9 and are excellent landscape plants, including in rock gardens. However, Russian sage is sometimes aggressive and can grow outside its intended space. If you want to get rid of the Russian sage in your garden, you can remove it manually or kill it with a chemical herbicide.
Water the soil with approximately 1 to 2 inches of soil two days before removing the Russian sage manually. Slightly moist soil is easier to dig in than extremely dry soil. Dig around clumps of Russian sage and dig about 8 to 10 inches deep to get all the roots. Adjust the digging as necessary to remove all the roots. Discard dug up Russian sage plants in the trash rather than the compost pile to prevent re-infestation.
Video of the Day
Apply a systematic herbicide on the Russian sage as an alternative to removing it manually. According to Ohio State University, the herbicide with the active ingredient prodiamine is effective in killing Russian sage. Apply directly to the leaves on a calm day. Read the herbicide's usage label and use accordingly. It is illegal to use herbicides in any other manner.
Remove or apply the herbicide continually whenever Russian sage sprouts grow back. It may take several months of persistent removal to kill the plants completely.