Frequently Asked Questions About Emerald Ash Borer

Photo: This group of tree lovers helped to plant 100 trees in the Slatterly Park neighborhood in October 2009. You can help plant trees and combat the Emerald Ash Borer at our next tree planting on April 24.

Answers below were provided by our City Forester, Jacob Ryg.

Why are we not attempting to treat Ash Trees with chemicals?

Answer: There are chemicals that work, but this is not an economical option due to the fact that you have to keep applying the chemical yearly or every other year as long as EAB is in the area. We are only going to treat a few specific ash in Rochester once EAB is found within 20 miles and not before. This practice follows the MN Department of Agriculture suggestions.

 

How many Ash trees are in Rochester?

Answer: About 22% of our urban forest.  Almost 7,000 boulevard trees, roughly 20,000 in city parks, and an unknown number which belong to homeowners (the DNR estimate is 50,000) Urban forestry experts recommend no species should occupy more than 10% of the total tree species.

 

Why not wait until EAB has arrived in Rochester to remove the trees?

Answer: Removing all Ash in Rochester at one time will compound the environmental effects.  Also, it isn’t realistic to demand such a large amount of resources from one city budget year.  Removals must take place over a 10-20 year period, in order to spread out the impact on the environment and our municipal budget. 

 

Do you think EAB is here yet?

Answer: We don’t know since the insect usually goes unnoticed the first four years it is present in an area.  There will be time once EAB is found in Rochester to protect individual trees via chemical injections. It is best to wait until advised to inject by the DNR & MN Department of Agriculture.

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