Declining Drake Elm

I have a drake elm, probably around 20 years old, that has been in decline for the past couple of years. This year it looks bad enough that I called a couple of tree specialists to ask their opinion.

One, a certified arborist, said it is not salvageable but wasn't sure exactly what was wrong. The other, specialist thought it was borer beetles and also said the tree was too badly damaged to recover. The 'sawdust' at the base of the tree apparently indicates some form of insect boring into the tree.

The first person offered no suggestions other than to remove the tree. The second person offered help in finding a new tree to locate in the same general area as this one after it is removed. He did not say the area around this tree should be treated because of the borer beetles. But, I am concerned about this because my husband wants to replace this tree with another drake elm.

What is the best way to move forward?

Yep, you have a major problem. Once you can see damage, the tree is essentially dead. The borers don't usually attack a healthy tree but if they are numerous enough, they will go for any tree. Are you seeing any close trees with the same problem?

When you cut the tree down, look for larvae. They are usually in the soft part of the branches or in the trunk. If you can identify the culprit, you can make a determination on what to do next.

Here is some information on borers that might help:

http://polk.ifas.ufl.edu/hort/documents/publications/Insect%20Borers%20of%20Trees%20and%20Shrubs.pdf

Thanks for the info. I have not noticed any other trees in the neighborhood with a problem like mine. From other tree forums, all say - as you have - that something else is/was wrong with the tree and the borers took advantage of it. When the tree is cut down, I will look for larvae. Perhaps, knowing exactly what kind of insect is feeding off the tree would narrow down the possibilities of what first went wrong - but from everything I've read so far, probably not.

I've heard that pruning is important to the overall health of this type of tree, as well as irrigation. While the watering I've done with the tree hasn't really varied much over the past 20 years, I've never had the tree pruned - never looked like it really needed it. That is, of course, until the decline started.

I've been told that if I use annual treatments of imidacloprid on a new drake elm, starting about 6 months after planting it, that it will help deter borer beetles. I need to read up more on this to see if this is a viable preventive step I can take should I plant a new drake elm. I think this treatment should also be used on the stump remnants once they are ground up to ensure any remaining beetles are killed.

I've never used Imidacloprid so not sure how it would work for you. We had bumper crops of flat headed borers in the Northern San Joaquin Valley of California. Luckily, I had a friend who was also a farmer and could get permits for some pretty ugly chemicals. It took about 5 years and about half my orchard but finally got rid of the borers. What I understood from her (farmer friend) was that the larvae started in the soil. One of the measures I took was to paint the trunk of the tree with latex paint as the borers lay their eggs in the crotches of the tree branches. And then, once a month, starting in the late winter and continuing for 5 months into spring, pouring the poison on the ground around the tree.

Daisy