Fletcher scales on my globe arborvitae? - Ask Extension
I have 6 globe arborvitaes in my front yard, they are there for 20 years, about 4 feet tall and wide. On Memorial Day I decided to trim them. Then I f...
Knowledgebase
Fletcher scales on my globe arborvitae? #753590
Asked June 02, 2021, 4:13 PM EDT
I have 6 globe arborvitaes in my front yard, they are there for 20 years, about 4 feet tall and wide. On Memorial Day I decided to trim them. Then I found out those small, brown, round bug attached to the stem. They seemed not moving, I can crush them by hand. About 1 in 10 is bright orange color. Upon searching I suspect they are fletcher scales. But there are just too many to handle. What can I do? Is there safe treatment? Will it affect other plants/trees? Shall I continue to trim the outside layer off to get rid of some scales?
Thank you.
Hennepin County Minnesota
Expert Response
It does appear that your arborvitae have fletcher scale, as you surmised. There are several treatments available for this pest, but one is to simply do nothing. Natural predators may eliminate the pests within a few years. You might also consider the use of horticultural oil or insecticidal soap. If these fail, there are several herbicides available to kill the scales. These are most effective when applied in mid- to late-June. There is no need to trim your arborvitae further. For more information, see
https://extension.psu.edu/fletcher-scale
https://www.canr.msu.edu/news/life_cycle_and_management_of_fletcher_scale_on_taxus_and_arborvitae
