Featured Expert
Jody Fetzer
Integrated Plant Management Specialist
Minnesota Landscape Arboretum
Chanhassen, MN

Q: I've noticed a yellow pattern on the leaves of my spirea. What could cause this?

A: Yellow patterns, particularly if they're very distinct, and if your plant tends to look very healthy and is growing just fine, might be caused by a virus. Now viruses are getting a lot more common in our gardens here in the arboretum, and I think in my garden at home. So be on the lookout for them. Some viruses are very easily moved around your garden. They may move on your tools, they may move on your hands. The best way to prevent that is to wash your hands and your tools in soap and water. Just dipping them in alcohol will not kill viruses. So, prevent their movement, but look closely for mosaic patterns that are yellow and green - they might look like a lightning bolt pattern. Just look for beautiful things on the leaves of your plant, and it could be caused by a virus infection. If the plant is getting along just fine with the virus, you can leave it in your garden. We're going to leave this spirea hedge here. It's beautiful, but it's infected with a virus. So, if it affects the bloom and the vigor of your plant, dig it out and throw it. Do not throw it in the compost pile - throw it in the garbage. Viruses are coming into our gardens, our perennials, and some of our woody plants. So, look for the mosaic, and get rid of the plant if it looks like it's affecting the health of your other plants.

images: infected spirea | yellow spots | flowers

The University of Minnesota is an equal opportunity educator and employer.
Online Privacy Statement

(none) /pyg/arb/qanda/1400/arb_1403.shtml
Last updated: Tuesday, February 01, 2005