Industry News: Tree Health

Q: Mature Chinese elm is dying--What is the cause?

Thursday, June 16, 2016  

Q: My mature Chinese elm is dying (I live in Glendale, Arizona). Let me set the timeline: In April 2015, I added a paver patio around the tree. The company that installed the pavers left a 4-foot diameter opening around the base of the trunk. There was a drip line to the base of the trunk as well, and the irrigation system is working well. The tree flourished during the summer of 2015, lost all its leaves in the winter, and then budded very nicely this spring. During this past week, I noticed a yellowing/drying on all of the leaves and was also surprised to see leaves falling from tree as if it were fall. It’s almost like something happened overnight. I will add that Arizona has had more than normal rain over this past year. Any idea what might be causing this tree to start dying? Thanks in advance.

A: Sometimes if a tree is planted incorrectly, it may take some time to show evidence of the problem. Some things to check for:

  1. The tree may be planted too deeply. There shouldn't be more than an inch of soil on top of the root ball.
  2. The tree may be planted too high. The root ball should not be exposed to the surface air.
  3. The tree may not be getting enough water. Make sure the root ball is being watered all the way around the tree and out at least 4 feet from the trunk and not just on one side or against the trunk.
  4. The tree may be getting too much water. Dig down on one side of the root ball to the bottom of it to see if the root ball is saturated and/or sitting in water. A moisture meter could also be used for this.
  5. Do not use fertilizer high in salts, such as chicken or steer manure, or high in nitrogen, such as 41-0-0. This will burn the roots.
  6. The pavers that were installed should have been pervious to allow water and oxygen to the roots. If impervious pavers were installed, or pavers were installed with mortar between them, they should be replaced on top of the root ball.

Responder: Ted Lebeshkoff, RCA #513, Arcadia, CA