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Ash Bark Beetles Are Back

We hope you had a good 2021 and that this upcoming year will be better for you. As you know, every February we send you the updated renewal for the Plant Health Care program on your trees.

There are usually minor changes to most renewals, but this year there is a significant change to all our customers that have Ash trees. Through December and January we sent out an arborist to measure and inspect every one of your Ash trees on your property. This was a huge undertaking because over half of all our customers have at least one Ash.

The reason we needed to measure the diameter trunk of your Ash trees is because we now strongly recommend applying a systemic pesticide to kill and keep the Ash Bark Beetle away. Over the past 3 years, the Ash Bark Beetle has become a major health risk to Ash trees as their numbers have increased dramatically. In 2021, the city of Grand Junction removed over 300 dead Ash trees and we removed several hundred dead Ash trees because of the bark beetle. These pests are such a problem that we have been planning with the city of Grand Junction and Rainbow Treecare Chemicals to come up with the best solution to get rid of them.

After years of research, we now know that a few systemic pesticides are working great against the bark beetle. Anytime we can apply pesticides systemically instead of a foliar spray, we will always recommend the systemic application. Systemic pesticides get way better coverage, last 1-2 years with one application and they don’t harm beneficial insects.

 When we first started treating Ash trees 3 years ago, CSU entomologists suggested using foliar sprays to control the ash bark beetle. Most of your Ash trees we have been applying a foliar spray 1 to 3 times per year. This type of application is effective, but the problem is one application only has a residual of about 2 weeks, we can’t fully cover large tall trees and these chemicals do kill beneficial insects.

Now the research has confirmed that systemic pesticides do work against the ash bark beetle and we are switching all of the applications to the systemic treatment. What this means is if your Ash trees are under 12 diameter inches, we will apply a systemic pesticide in the ground that lasts 12 months. If your Ash trees are over 12 diameter inches we will apply a systemic pesticide into the trunk that has a 2 year residual.

Remember that pesticide treatments are most effective when the trees are taken care of properly all year long. You must make sure they are getting watered in the growing months and in the winter months. Applying fertilizer 2-3 times during the growing months is also very beneficial.

Please call the office if you have any questions and would like to talk to one of our five Certified Arborists about this or any other service on your renewal form. 

Teddy Hildebrandt

Author Teddy Hildebrandt

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