The American White Ash and Green Ash trees have become fixtures in many new neighborhoods. They are planted for good reason: their vibrant fall color, hardiness, durability and predictable growth habits.
Many landscape companies and land developers also like to plant them because they are easy to transplant and seldom die, even in harsh construction zones.However, soon after new houses get filled with families and the homes become part of a community, they are followed by another new resident: the ash bark borer, a common pest in newer suburban areas such as Highlands Ranch, Broomfield, Erie and Aurora.
The Ash Bark Borer attacks stressed trees. Signs include small leaves, below-normal twig growth, poor leaf color and early leaf drop.
Transplanting shock can create a high amount of stress in newly planted ash trees, too.
The adult ash bark beetle creates a small hole in the bark as it exits the tree in summer. Frass (sawdust) can often be found around the hole or at the base of the tree. These holes are most commonly found on the main trunk and larger branches. Trees that have been attacked repeatedly may have a distorted trunk and areas of dead wood exposed.
Once the insects are inside the tree, they cannot be controlled, so preventive sprays should be applied. A preventive borer spray can be easily applied in April to small ash trees with a hand held or backpack sprayer. As a tree matures, the stress within the tree will be reduced, and it will become less of a target to the ash bark beetle.
– Robert Brudenell is a registered Consulting Arborist and Master Arborist. He owns The Natural Way Inc. in Englewood.
