Bark peeling off weeping and globe willow trees - Ask Extension
We have three very large globe willows. All of them have severe bark peeling off. It also happened to our willow tree but the bark peeled almost all t...
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Bark peeling off weeping and globe willow trees #320027
Asked May 09, 2016, 12:45 PM EDT
We have three very large globe willows. All of them have severe bark peeling off. It also happened to our willow tree but the bark peeled almost all the way around the trunk and it is mostly dead. It does seem to be more on the southwest side (most sun) and we had a lot of snow, but I don't see discoloration from sun scald. There are no cankers, insects or fungus that we can see. Is there anything we can do to save the other 2 trees?
Larimer County Colorado
Expert Response
Hello,
Sometimes when trees are drought stressed, the cells may shrink and the bark becomes loose due to the constriction of the cambial tissues (where the xylem and phloem and growth cells live). This can cause the bark to slough. Another factor could be sunscald, like you mentioned, which actually causes the bark to split due to freeze/thaw. Frost cracks, which are also temperature-related, can cause the bark to split.
The biggest thing to consider is if the wound is down to the cambium. It's hard to tell on the photos....if it was simply the bark that shed, the cambium may be fine. The bark acts like a protective barrier, of sorts.
That said, the trees have definitely been stressed in the past. Willows and globe willows are fairly short lived trees and these look quite large. They are susceptible to storm damage, and even though they grow quickly, can be easily damaged by winds. They are also trees that have a higher use needs, so may become damaged by drought or inconsistent watering.
Another possible factor affecting these trees is slime flux/bacterial wetwood, which is a disease stemming from stress (particularly drought): http://www.ext.colostate.edu/ptlk/1438.html
If these are trees you'd like to save, then bump up irrigation during the entire year--including fall and winter. They are growing in turf, so you may have to run the irrigation system a couple extra times per month to give the trees extra moisture. Make good pruning cuts and keep the trees as healthy as possible.
Sometimes when trees are drought stressed, the cells may shrink and the bark becomes loose due to the constriction of the cambial tissues (where the xylem and phloem and growth cells live). This can cause the bark to slough. Another factor could be sunscald, like you mentioned, which actually causes the bark to split due to freeze/thaw. Frost cracks, which are also temperature-related, can cause the bark to split.
The biggest thing to consider is if the wound is down to the cambium. It's hard to tell on the photos....if it was simply the bark that shed, the cambium may be fine. The bark acts like a protective barrier, of sorts.
That said, the trees have definitely been stressed in the past. Willows and globe willows are fairly short lived trees and these look quite large. They are susceptible to storm damage, and even though they grow quickly, can be easily damaged by winds. They are also trees that have a higher use needs, so may become damaged by drought or inconsistent watering.
Another possible factor affecting these trees is slime flux/bacterial wetwood, which is a disease stemming from stress (particularly drought): http://www.ext.colostate.edu/ptlk/1438.html
If these are trees you'd like to save, then bump up irrigation during the entire year--including fall and winter. They are growing in turf, so you may have to run the irrigation system a couple extra times per month to give the trees extra moisture. Make good pruning cuts and keep the trees as healthy as possible.