Inner yellowing of emerald green arborvitae - Ask Extension
I bought 65 arborvitae trees from Menards in April. They are were about 6-7' tall. Around July I noticed that on some lower small areas the leaves...
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Inner yellowing of emerald green arborvitae #368095
Asked October 05, 2016, 7:21 PM EDT
I bought 65 arborvitae trees from Menards in April. They are were about 6-7' tall. Around July I noticed that on some lower small areas the leaves turned black. I cut them off in case it was mold or a fungus as I didn't want it to spread. Now we come to October and I noticed that the entire inner of the trees are yellowing. They have grown at lease a foot and have gotten wider. I had them planted approximately 32-36" apart for use as fencing. Is this normal fall yellowing? Do they need more water? We dug down with just couple inches and soil is black and moist. No one seems to know anything about arborvitae trees. Please Help!!
Saginaw County Michigan
Expert Response
This is a duplicate of the question answered by John Harville. His resonse covers the issues, so I will close this as a duplicate. Thank you.
Hello again,
I see Mr Harville's response was in July. So now you are seeing more issues. It sounds like you didn't have an arborist out. Since you had good info on how to keep them watered properly, this isn't likely a problem. The inner leaves of arbs, like all evergreens, do age out and turn yellow and drop. On arborvitae this happens on 2-3 year old leaves. So, the inner leaves of your shrubs can be turning yellow and dropping. Here is info from Univ. of Georgia Extension---
"Needles of evergreens like junipers, pines or arborvitae shed their oldest leaves or needles in late summer or early autumn. Most pine trees drop their needles in the fall. Some species may drop needles at other times. The natural yellowing of the older needles occurs uniformly from the top to the bottom of the tree. Newer needles at the tips of the branches stay green.
The needles on most evergreens usually last three years, although some juniper needles may last a decade or more. Arborvitae and white pine needles turn brown, yellow or reddish-tan and drop in the autumn of the second year. Arborvitae sheds branchlets rather than needles, which usually turn brown as they age, yet remain on the tree for quite some time before falling."
So, as long as you are giving good care and the outer leaves are staying green, your shrubs are fine. One other thing that may cause the inner brown leaves to 'drop early' are the activities of sparrows and other birds that make their winter home in the shrubs. Their flying in and out of the shrubbery, a natural process, can shake off the older brown leaves and make the process of dropping the leaves more obvious to us.
Again, if you feel the shrubs are in trouble the best thing you can do is have a certified arborist out to assess their health on site. Find a couple at www.treesaregood.com, get an estimate and choose one to come out. Thank you, again, for using our service.
