Protect Your Ash Trees

Identifying Ash Trees

Before you can determine if you have an Emerald Ash Borer (EAB) problem, you must first identify whether or not you have ash trees. Use these common criteria for identifying ash.

Photograph by Keith Kanoti,
Maine Forest Service,

Ash trees feature compound leaves made of 5-11 leaflets. Ash leaves also have opposite budding, with leaflets being directly across from each other.

Like their leaves, ash tree branches are also directly across from each other — not staggered.

Young ash trees will have relatively smooth bark, while mature trees will have tight bark featuring distinct diamond-shaped ridges.

When present, ash tree seeds will usually be clustered together as dry, oar-shaped samaras.

MSU Extension Bulletin E-2941, May 2005

Signs Of Infestation

Here are some helpful tips on what to look for in you ash trees for signs of stress and infestation.

Emerald Ash borer (EAB) Adult
Metallic green-colored adults emerge in early summer to feed on ash foliage and lay eggs on bark. Little noticeable damage is caused by EAB adults.

Photograph by Leah Bauer, USDA Forest Service Northern Research Station,

EAB Larvae
Eggs hatch into larvae during late summer and fall. Larvae tunnel into trees to feed under the bark, thereby destroying the tree's ability to transport water and nutrients. Larvae leave S-shaped galleries under the bark of the trunk and branches.

Photograph: Pennsylvania Department of Conservation and Natural Resources - Forestry Archive,

The Next Year
Larvae spend the winter under the bark, pupate into adults, and emerge in early summer. As the adults exit the tree, they leave behind D-shaped exit holes. Eggs are laid soon thereafter and the destructive cycle begins again.

Photograph by David Cappaert, Michigan State University,

Check Your Ash Trees For Signs of Stress

Bark Splitting
Photograph by
David Cappaert

Canopy dieback
Photograph by Jason Sharman,

Epicormic shoots
Photograph by
David Cappaert

woodpecker activity
Photograph by Joy Viola,
Northeastern University,

Can Your Ash Tree Be Saved?

Photograph David Cappaert,
Michigan State University,

Healthy trees can still be saved from EAB. Follow these easy steps to help you identify if your ash trees can be treated with Bayer Advanced Tree and Shrub product line.

Are your trees:

  • Healthy and growing with more than half their leaves
  • Less than 20” in diameter at chest height
  • Showing only few outward signs such as woodpecker damage, bark splits and water sprouts at the tree base

If your tree fits these criteria, Bayer Advanced may be for you. If your tree doesn't fit these criteria, contact a certified arborist in your area.

Protect And Feed Your Trees

Use Bayer Advanced 12 Month Tree & Shrub Protect & Feed Liquids to keep your ash trees healthy and happy.

  1. Provides 12 months of systemic protection with one application
  2. Provides slow-release fertilizer
  3. Protects entire tree or shrub — especially new growth
  4. Prevents damage from destructive insects like Emerald Ash Borers, Japanese Beetles (Adult), Leafminers and other listed pests
  5. Just measure, mix and water in