Daily Archives: October 5, 2021

Emerald Ash Borer Damage

Emerald Ash borer was discovered in Warren County, Kentucky back in July of this year 2021. Since Emerald Ash Borer was found in Kentucky in 2009, it has progressively spread throughout the state and destroyed several of our prized ash trees. The damage caused from Emerald Ash borer feeding brings on a lot of questions from Kentucky homeowners on: What control options are available? What trees can be replanted after the ash trees decline? These questions are all going to be answered in episode 17 of the Sunshine Gardening Podcast! In this episode, I chat with University of Kentucky Forestry Health Extension Specialist Dr. Ellen Crocker to ask specifically what options are available for Kentucky residents. To listen to the full episode, make sure to stay right here on the Sunshine Gardening Podcast!

Tell us more about the emerald ash borer and what damage it causes to Ash trees in Kentucky.

The emerald ash borer is an invasive insect from Asia. It is actually a beetle. Our ash trees do not have a good defense mechanism to them. It can rapidly kill ash trees.

Since it was first discovered in Michigan in 2002 and since that time, it has swept through the country. It has killed millions of ash trees. Just this past year, especially in Western Kentucky there have been several new sightings. Larvae tunnel and kill the vascular tissue of the tree. Most homeowners will miss the insect damage. Less healthy tree? Missing part of the tree? Lots of damage done from the feeding. “D” shaped exit holes are found on the outside edge of the tree due to the shape of the abdomen.

In Kentucky, we have several varieties of ash. White and green ash trees are the most damaged. The blue ash have more natural resistance to it.


What homeowner options are available to help control this invasive insect pest?

Ask yourself “do you have ash trees on your property?”

You can apply yourself or contact a certified arborist in your area to apply the insecticide. There are several insecticides sold for control of emerald ash borer. Soil drench with imidacloprid to treat annually. Make sure to follow the label directions. Application amount is based on how big the trunk diameter is in size.  Treat annually with imidacloprid.

Certified arborists are paid professionals through the International Society for Arboriculture (ISA).

A few other things to consider about treating trees for EAB. Look at it as a protective insecticide application. The insecticide are systemic insecticides. So it may or may not be effective. Prioritize the trees that you want to save. Consider the costs associated with them. Time treatment according to the timing of the emerald ash borer.


What challenges does that bring to the woodlands or in the landscape?

Ash trees deteriorate rapidly. However, it doesn’t hurt the wood. Unfortunately, when they start to go downhill, they break apart. Other things start to happen when the tree can’t defend itself anymore. Ash are pretty hazardous to work with. Harvest your ash trees and offset the costs. In some properties, it can be 20-30 percent. Reach out to foresters in your local area. Consulting foresters will help you with making decisions.


Can you recommend other trees for replacing damaged ash trees?

Learn from the elm tree story. Replace with more than one species of tree. I recommend planting with a diversity of tree species. Consider a diversity of native species. We have an abundance of native plant species in the United States. Kentucky has over 100 native tree species. Pick the right tree for the right site. There is more than one choice. Take note of how wet the area and the soil type. Do you power lines overhead? Maybe you can choose something smaller. Looking for ideas? Visit a local garden or arboretum to get ideas.

A few of Dr. Ellen’s favorite trees:

Large shade trees: Oak species. Good shape. Good for wildlife.

Great fall color? Black Gum is an underused tree that has good fall color.

https://www.uky.edu/hort/Black-Gum

Statement piece for winter?

  • Kentucky coffee tree.

https://www.uky.edu/hort/Kentucky-Coffeetree

  • Catalpa tree.

https://www.uky.edu/hort/Northern-Catalpa

Smaller trees? Yellow wood. Serviceberry.

https://www.uky.edu/hort/Yellowwood

https://www.uky.edu/hort/Downy-Serviceberry

Laurie Thomas, Extension Forester with UK Forestry and Natural Resources spotlights a Native Tree of the Week during From the Woods Today program. To find out more information, go to https://anr.ca.uky.edu/tree-week-0.

KY Invasive Plant Council- native alternates to invasive plants

If someone wanted to learn more about emerald ash borer, what resource or website would be good for them to visit?

University of Kentucky Extension Entomology’s Department for Emerald Ash Borer: https://entomology.ca.uky.edu/entfact/kentucky-emerald-ash-borer-eab-resources-updates

Purdue University Emerald Ash Borer Cost Calculator: https://int.entm.purdue.edu/ext/treecomputer/


I hope that you enjoyed our discussion today on the Emerald Ash Borer and the damage it can cause. A special thank you to Dr. Ellen Crocker for providing her expertise and being a guest on the Sunshine Gardening Podcast!

If you would like to see the show notes from Episode 17, make sure to visit me on the blog at Warren County Agriculture. You can find us at warrencountyagriculture.com. Thanks for listeners gardeners! As always, keep digging into gardening and remember to add a little sunshine!