Boxwood yellowing on some of the 20 boxwood in my front yard.

Asked February 29, 2020, 12:03 PM EST

I have noticed the yellowing this year, not previous years. Boxwood bushes were well established when we moved here in 2012, not sure how old they are. There is stippling on the leaves and small black spots on the back of some of these yellow leaves. I have lost one boxwood completely, turned completely yellow and dry. I have sent in a soil sample in the last week, still awaiting results. Any suggestions on what the issue is and what can be done to save the boxwood?

Montgomery County Maryland

1 Response

This does not look like a disease or insect problem. It looks like a type of root problem which may include site conditions, environmental issues, voles, etc.
Voles are a type of meadow mouse that feeds on the roots of trees/shrubs, etc. Remove the leaves and check around the base of the plants for silver dollar size holes and look for gnawing on base of stems which can cause dieback.

We recommend a wait and see approach. Check the drainage in the area and make sure the soil drains well and check for vole damage. Make sure mulch is no thicker than several inches and keep away from the base of the stems.
Wait for new growth and then prune out affected branches. Proper pruning includes thinning. Boxwoods have growth buds all along the stem. Hopefully, the plant should put out new growth. Monitor the plant throughout the growing season for additional symptoms.
Here is our page on boxwoods and a pruning video
https://extension.umd.edu/hgic/topics/boxwood-decline
https://www.youtube.com/watch?v=3i8mcoKapeY&t=7s

Marian