Help! ArborVitae turning brown

Question: We planted 16 arborvitae in June.  They’re turning brown which seems to have started with one plant and is spreading. It seems to now be starting on the inside of the adjacent plants but is sometimes is a patch near the edge.

responder: Thank you for your question!   Laura S.      Michigan State University Extension Advanced Master Gardener Volunteer You may also contact the toll free MSU Extension lawn and garden hotline at 1-888-678-3464 with your gardening questions or visit www.migarden.msu.edu for Smart Gardening resources. Replied September 20, 2024, 11:03 AM EDT
response: Hello This is likely transplant shock. All trees and shrubs go through this upon transplanting because they must establish new roots. Plants this size will take 2-3 yers to establish.  Dig down 8-10 inches after you water to see if soil is moist. You want moist soil, not soggy and not dry. Water early in the day so foliage is dry by sunset if you use a sprinkler that wets the needles. It is best to use a soaker hose at the base around both sides of the hedge. A quick connect type makes it easy to leave the hose in place in between waterings. Water these shrubs at least once a week in clay or loamy soils, 2-3 times a week in sandy soils. Water until the ground freezes.  Next spring through fall water in the same way when no substantial rain is expected that week(3/4- 1 inch of rain). Again, keep the shrubs watered up to when the ground freezes next year.  All evergreens need to go into winter well hydrated, but not drowning. A layer of mulch 2-3 inches deep and not touching the trunks or lower foliage will help retain water, discourage weeds, and make it easier to mow around the hedge.

responder: The Question Asker Replied September 20, 2024, 12:56 PM EDT
response: Thank you for all of this great info. My husband said when he waters he has been watering up and down the whole plant and that lots of little bugs (gnat size) fly out? Could we have an infestation of something? Thanks Sent from my iPhone  On Sep 20, 2024, at 11:03 AM, Ask Extension wrote:    ﻿

responder: Thank you for your question!   Laura S.      Michigan State University Extension Advanced Master Gardener Volunteer You may also contact the toll free MSU Extension lawn and garden hotline at 1-888-678-3464 with your gardening questions or visit www.migarden.msu.edu for Smart Gardening resources. Replied September 20, 2024, 1:19 PM EDT
response: Hi Insects wouldn’t cause browning like that. But, be sure the branches will dry by sunset. A slow drip from a sprinkler barely on, or soaker hose, all around the roots is the best way to water, getting soil moist down 6-8 inches each time.  If you would like, you can submit your pictures to MSU Plant Diagnostic lab for their opinion. Email your pictures and question to <personal data hidden>  You may also submit branch samples to the lab for their analysis. They will need a branch that still has green needles on it. And there is a fee for that service. Instructions and how to sample are on their website.

responder: The Question Asker Replied September 21, 2024, 9:24 AM EDT
response: Thanks! Sent from my iPhone  On Sep 20, 2024, at 1:19 PM, Ask Extension wrote:    ﻿