Arborvitae is dying - Where do I turn for help?

Asked May 14, 2016, 3:19 PM EDT

We just moved into a new home with a row of pretty tall arborvitae, and unfortunately we don't have much experience or knowledge about them. The arborvitae on the end is completely brown and I assume it's dead. The one next to it, and the arborvitae on the far end of the row, have some browning as well, but not nearly as much. Do you have any advice on what to do at this point or who to call for advice/help? We really don't want to loose the entire row of arborvitae. Since the home is new to us I don't know how long this has been happening. Sorry about the poor quality of pictures, but hopefully they can give you an idea of what it looks like. I really appreciate any input you may have.

Clackamas County Oregon

1 Response

I'm sorry to hear about your arborvitae. Typically when you see browning of arborvitae like in the pictures you attached, there is either too much or too little water. Arborvitae requires moist soil, but too much water can cause root rot, which kills root tissue, impairs water and nutrient transportation, and subsequently causes leaf browning. Check the soil around the tree to see if there is poor drainage. There has also been a lot of drought damage to trees in our region from the past few hot, dry summers. Sometimes drought damage is not visible until the following spring, so you may be seeing damage from last year's drought. You can prevent this kind of damage by watering your arborvitae with a soaker hose about once a week during the summer, but make sure not let the tree sit in a pool of water.

There is also a chance that an insect pest in responsible for the leaf browning. You might check to see if you see any signs of insects (e.g. frass (saw dust-like insect excrement), eggs, holes in the trunk or branches, tunnels on leaves, webs, small scurrying mites that look like black dots, sticky sap, etc.).

If you would like to have someone come out to inspect your tree, you might consider contacting a certified arborist. For a list of certified arborists in your area, check out the International Society of Arboriculture website.

Please let me know if you have any additional questions.