Answer: When trees die from the top down, it usually indicates a root problem. It could be drought related or it could be root rot from poorly draining soils. Dig down and check on your watering to be sure it is effective. The rule of thumb is an inch or two of water a week from the sky or the hose. It should be applied in a slow deep soaking to the root zone for best results and the root zone should be covered with several inches of organic mulch to help keep the soil cool and moist. If you find the soil moisture adequate when you dig down, then the problem might be root rot. There's not much you can to do save a tree once the symptoms are apparent.
Best wishes with your trees!
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