Maple leaf browning? Heat or trunk damage?
We planted two maples in June 2017. Two months later I've noticed the leaves on the autumn blaze changing colors and some dead and browning leaves. We were watering almost everyday by sprinklers during this time because of the new sod and 90+ degree temperatures. But I'm wondering if the trees are not getting enough or is there another problem, like the weed whacker damage? How can I make sure my maples are healthy?
Adams County Colorado trees and shrubs
Newly planted trees are very susceptible to over and under watering. We recommend wanting with 10 gallons of water per inch of trunk diameter per watering. Ideally you would check soil moisture regularly and water when the top few inches of soil are dry.
The string trimmer damage is stressful for the tree in couple ways. The tree has to spend energy closing the wound and fighting decay. The tissues damaged and removed by the string trimmer also are part of the system that moves water and nutrients through the tree.
Does the damage go all the way around the tree's trunk? If it does, the tree will probably not make it. Even it just goes most of the way around, the tree may struggle to recover. We recommend placing a ring of wood chips or other organic much around tree partially to avoid this sort of damage.
At this point all you can really do is give the tree the best care you can. Follow the above watering instructions and consider winter watering once a month or so if we don't have significant precipitation. Do not prune any living wood out of the tree or fertilize it. If the tree does make it or you are planting new trees we have resources on tree planting and care which can be found here:http://static.colostate.edu/client-files/csfs/pdfs/TreePlanting_636.pdf
and here: http://www.ext.colostate.edu/mg/gardennotes/635.pdf
I hope this helps, please let me know if you have further questions.