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Question from Angie, Hyde Park, UT (received 5/8/20) -

I have a couple different varieties of maples that are coming out of dormancy, and for the second year in a row, the tips of the branches have no leaves and appear black/brown. Last year, I assumed it was fireblight and pruned and sprayed a copper fungicide.
What could be ailing them and how should I treat it?

Answer from Dr. Mike Kuhns, USU Extension Forester and Professor (sent 5/12/20) -

Angie,

The photo is blurred, but it appears to be an ‘Autumn Blaze’ maple and if not that, some other maple related to red maples (‘Autumn Blaze’ is a hybrid between red and silver maples). They grow well but get very chlorotic (yellow) in Utah’s high pH soils because the high soil pH limits iron availability. They end up not having enough chlorophyll in their tissues which leads to yellow or almost white leaves that are easily damaged by the sun and often turn brown or black. The most tender tissues are in the tips of the branches, so that is where the damage would be the worst. There is little you can do about iron chlorosis other than choose trees that are well adapted to high soil pH. Silver maple and its hybrids are the worst and red maples are close behind. The main treatment for chlorosis is to add iron chelate (chemicals like sequestrene) to the soil and water it in. However, it takes a lot, it is expensive, and at best it only lasts a year. Acidifying the soil would be a great alternative except lowering soil pH enough to make a difference is not possible.

Addition information on iron chlorosis in trees.