Emerald Ash Borer

Published on
February 15, 2024 at 8:44:04 AM PST February 15, 2024 at 8:44:04 AM PSTth, February 15, 2024 at 8:44:04 AM PST

It’s time to talk about a silent but deadly threat lurking in our midst: the Emerald Ash Borer. This tiny but mighty pest has been wreaking havoc on millions of ash trees across the Midwest, leaving a trail of destruction in its wake. But fear not, for knowledge is power!

Keep an eye out for telltale signs of infestation like canopy thinning, D-shaped exit holes in the bark, and sprouting at the base of the tree. Early detection is key to saving your beloved ash trees, so stay vigilant and arm yourself with the know-how to combat this insidious invader. Your trees will thank you for it! 

How To Identify Ash Trees 

  • Mature tree bark is gray-brown with deep cracks
  • 7-13 leaflets on each leaf
  • Leaves are on the opposite sides of the stem
  • Leaves are green in the spring/summer and the fall color will be yellow on a Green Ash Tree or purple on a Purple Ash Tree
  • Winter buds are black in color 

Emerald Ash Borers have a 1 year life cycle: 

  • Egg – Adults lay eggs late May to late July
  • Larvae – Eggs hatch late July, and larva eats through tree late July through October
  • Pupae – Larvae pupate and overwinter beneath the bark of ash tree
  • Adult – Emerges in the spring 

Signs of Emerald Ash Borer Damage 

  • Crown (top of tree) die back on mature trees
  • “D” shaped holes in the bark
  • “S” shaped feeding galleries under the bark
  • Woodpeckers feeding on damage of bark
  • Low sprouting (suckers) branches on the trunk of the tree
  • If your tree shows any sign of damage, contact your county extension office or city arborist. 

Emerald Ash Borer Management Strategy 

To get the most out of your existing ash trees, use these preventative measure to protect your trees.

  • Treat your existing ash trees in the spring or fall with Annual Tree & Shrub Insect Control
  • Remove all organic matter (leaves/mulch) around the base of tree. This allows the insecticide solution to go directly into the soil.
  • Apply Annual Tree & Shrub Insect Control when soil is moist, but not saturated at the base of the tree using a watering can, not a bucket due to run off. May take up to eight weeks for larger trees to be effective.
  • Fertilize and water your trees as needed. A healthy vigorous tree is less likely to be attacked. We suggest using root feeder or fertilizer spikes.
  • Plant different type of tree nearby for the future. It is assumed that no control measure will be 100% effective over time. 

Tree Alternatives to Replace Ash Trees 

Your local Earl May offers a wide variety of great shade trees to consider planting.

  • Oak – Bicolor, Burr or Red
  • Red Maple – Autumn Blaze, Brandywine, Matador or Sun Valley
  • Linden – Greenspire or Shamrock
  • Locust – Skyline
  • Tulip Tree
  • Hackberry
  • Aspen
  • Birch