Discoloration on Arbor Vitae Trees - Ask Extension
We are quite sure the discoloration is the result of a spider mite infestation, and we are working hard with neem oil, water spraying, and insecticida...
Knowledgebase
Discoloration on Arbor Vitae Trees #483057
Asked September 05, 2018, 4:10 PM EDT
We are quite sure the discoloration is the result of a spider mite infestation, and we are working hard with neem oil, water spraying, and insecticidal soap to get rid of them. We are also going to get some ladybugs. We would like to know, though, if we should just leave the discolored, brown sections in place or prune them back. Will the evergreen branches regenerate if we leave them in place? Or should we just cut the branches back?
Montgomery County Maryland
Expert Response
We don't think that this is the work of spider mites.
It looks more like a root problem. The pattern of damage all to one side suggests that there has been a major disruption to most of the roots with the exception of the one attached to the portion of the tree that is still green.
Unfortunately, the parts that are brown are almost dead and not coming back.
Most evergreens can not resprout from brown wood.
You could trim them off and see what is left, but it's likely the portion of the green side will be brown where it meets the rest of the plant.
So it's probably time to remove it.
cm
It looks more like a root problem. The pattern of damage all to one side suggests that there has been a major disruption to most of the roots with the exception of the one attached to the portion of the tree that is still green.
Unfortunately, the parts that are brown are almost dead and not coming back.
Most evergreens can not resprout from brown wood.
You could trim them off and see what is left, but it's likely the portion of the green side will be brown where it meets the rest of the plant.
So it's probably time to remove it.
cm
This is very discouraging. If we remove all the dead limbs this fall, should we attempt to dig up the roots or replant the tree? Or just leave it and see if the rest dies? I am so confused by this diagnosis because we have had the tree for three years, and it was doing great until a few weeks ago, when so much of it turned brown. It was the tallest, healthiest, and most robust of the three trees we have. So all this doesn't make sense to me, but I don't know that much about it.
It is mid-September, and we are in Maryland, Montgomery County. If we decide to replace the tree, do we have time to get a new plant started before winter?
Thank you.
It is mid-September, and we are in Maryland, Montgomery County. If we decide to replace the tree, do we have time to get a new plant started before winter?
Thank you.
This is very discouraging. If we remove all the dead limbs this fall, should we attempt to dig up the roots or replant the tree? Or just leave it and see if the rest dies? I am so confused by this diagnosis because we have had the tree for three years, and it was doing great until a few weeks ago, when so much of it turned brown. It was the tallest, healthiest, and most robust of the three trees we have. So all this doesn't make sense to me, but I don't know that much about it.
It is mid-September, and we are in Maryland, Montgomery County. If we decide to replace the tree, do we have time to get a new plant started before winter?
Thank you.
It is mid-September, and we are in Maryland, Montgomery County. If we decide to replace the tree, do we have time to get a new plant started before winter?
Thank you.
Evergreens can hide their stress for a long time. Consider a typical retail fresh Christmas tree, which can be completely severed from it's roots in October, and still be green through the new year.
We would lean towards pulling the tree out. Look at the base of the tree trunk and see if it looks like it goes straight into the ground like a telephone pole, or if you can see the gentle widening or flare before it goes into the ground. If you can't see that, it may have been planted too deeply, which can kill a tree over time.
Look at the roots and also for signs of bark damage around the trunk- sunken areas, sloughing bark, rodent chewing damage.
We would suggest waiting until early spring to re-plant so that the roots can get a start before winter.
cm
We would lean towards pulling the tree out. Look at the base of the tree trunk and see if it looks like it goes straight into the ground like a telephone pole, or if you can see the gentle widening or flare before it goes into the ground. If you can't see that, it may have been planted too deeply, which can kill a tree over time.
Look at the roots and also for signs of bark damage around the trunk- sunken areas, sloughing bark, rodent chewing damage.
We would suggest waiting until early spring to re-plant so that the roots can get a start before winter.
cm
