Ask Burton: Q: I have Japanese maples in a very shady spot; they’ve been planted for four years and have been beautiful. They’re showing a lot of burning around the leaves this year, and these plants are not new. We made sure to water everything carefully. Any idea why this is happening?

A: The month of July happened! In all seriousness, we had excessively high temperatures in July, as you know. Japanese maples can only pull water out of the ground so fast; you probably were watering exactly as you should. After growing the trees in that spot the past four years, you likely have a pretty good idea how to water them, but these plants just don’t care for sustained temperatures of 105+ degrees.

The heat dried the edges of your leaves, even while the roots were adequately watered. A few things to help if you run into excessive heat spikes again:

  • Mulch your beds to a depth of at least 2 inches.
  • Lightly water the surface of the soil each morning when it gets that hot just to kick a little more humidity into the air.
  • Rig a temporary shade cover or use a pool umbrella during that type of heat spike if the plant is in a feature area, or is still small enough for this to be practical.

In any case, your plants ought to be perfectly fine when the temperatures cool, with a modest flush of new growth as we go into the earliest part of Fall. Next spring, every leaf which has been burned now will be replaced, and your plant should look good again.