How can you kill out Japanese anemone in an established perennial bed? It ends up taking over before summer’s end! Am I going to have to start all over and kill out everything?
The Gardener’s Answer
Hello, Christee: The good news is that you certainly do not have to start all over again. Some perennials spread more than others and Japanese anemone, once they become established, can spread rapidly. Japanese anemone species hupehensis, tomentosa, as well as the hybrids, are herbaceous perennials that really put on a show in the fall garden. They can reach up to 5 feet tall and 3 feet across. They are available in single, semi-double, and double blooms ranging in color from white to lilac. These fibrous-rooted perennials can be thinned out so they do not take over the garden. Spring is a good time to do this so as soon as you see the foliage coming up in your garden, get out the hand trowel and start dividing. This will keep them in check and free up space needed for your other perennials. Share your divisions with your gardening friends or donate them to your county Master Gardener program. They will likely have a spring plant sale and will be happy to take them off your hands. If you find that later on in the season you did not remove enough, you can always take more out. It will likely be harder to dig out and may not transplant well at this time of year, but for your purpose it will get the job done.