Techney arborvite Browning and needle loss.

Asked August 9, 2017, 1:24 PM EDT

Since this spring 7 arborvites in a row have been having needles Browning and falling off. The new growth stays alive as seen in pics.tree tops are less affected. I have other trees further away that are unaffected. The trees were planted spring of 2016. Thanks for your help

Monroe County Michigan shrubs arborvitae browning needles

1 Response

Hello,

There are several possibilities. Compare what you have to the pictures and descriptions in the links below---

https://extension.umd.edu/hgic/arborvitae-leafminer-trees-and-shrubs

http://extension.psu.edu/pests/plant-diseases/all-fact-sheets/arborvitae-diseases

The following link lists some fungicides available to the homeowner.

https://ag.umass.edu/landscape/fact-sheets/arborvitae-needle-blight

If you want help getting a positive ID on exactly which disease or pest might be affecting your shrubs you can submit samples for identification to the MSU diagnostic lab. Instructions, sample submission form and fee schedule are on their website.

https://pestid.msu.edu

Since your shrubs have only been planted for the last 18 months they are still under transplant stress. I see you have drip irrigation around them- very good! Keep these shrubs well watered until the ground freezes in the fall. Shrubs that are well hydrated going into winter have much better health and survival rate then shrubs which are not well watered. You don't want the soil sopping wet, it still needs to be well drained. So, if your soil is clay you will be watering much less then if your soil is sandy. A temporary soaker hose on a battery operated timer can be used after your in-ground system has been winterized. This is important for the first 3-4 seasons after transplanting (used when fall rains are lacking) until the root system is well developed.

I hope this information is helpful, and thank you for using our service.