Knowledgebase
Japanese Anemone Pest/Disease #871138
Asked June 02, 2024, 12:16 PM EDT
For a couple years now I have observed issues with this japanese anemone. It is on the east side of the house with full morning sun. Some of the the leaves are fine but some growth develops brown spots or the entire leaf truns dark. Some of the leaves curl. There is a spirea bush nearby that grows fine/unaffected but the hydrangea nearby developed spots on the leaves last year. Am I worried about a virus or something in the soil? I tried thinning some of the patch last year but the problem still exists. Also the blooms have been completely unaffected. What can I do to prevent this? If more photos are helpful, please let me know.
Washtenaw County Michigan
Expert Response
Hello Brenna,
I believe the culprit is the four-lined plant bug which is in many landscapes right now and it sucks on many different species. It is a sucking insect which causes those yellow indents in the leaves. The yellow indents turn into black spots and cause the leaves to curl. Because its feeding period is brief, little control is necessary. However, if control measures are desired, insecticidal soap, horticultural oil or neem oil can be effective, especially against the nymph stage of the insect. Remember, when using chemicals, make sure that the label lists the specific insect that you are using it against and follow the use instructions on the label.
I’m attaching an article about the four-lined plant bug for your information.
https://extension.umn.edu/yard-and-garden-insects/four-lined-plant-bugs
Thank you for contacting Ask Extension.
