Green Giat Arborvitae leaf browning

Asked May 27, 2020, 8:36 AM EDT

I have 9 green giant Arborvitae which are 4 yr old. Last year spring I notice two which had selective leaf browning at the base and the whole stem later died. One plant had 3 stems and other had 2 stems so I cut those and there were no issues later. This year again one of the plant which had 3 large stem browning that I had to cut is again showing one of the branch browning. The rest of the plant appears healthy. There does not seem to be less water but perhaps slightly more saturated soil from neighbors yard but there is no water logging. If I cut these branches I will soon have no tree.

Henrico County Virginia

1 Response

Thank you for your question and pictures.

The Virginia Cooperative Extension entomolgist reviewed the pictures and provided the following information:

Spotting on needles from Spruce Mite. Likely contributed to the discolored section. Mite damaged sections often appear discolored.

Treat with dormant oil in late winter before bud break or with insecticidal soap in early May. Treat with insecticidal soap in late September.