How To Treat Emerald Ash Borer

Updated Jun 27, 2017
Photo: David Cappaert, Michigan State University, Bugwood.orgPhoto: David Cappaert, Michigan State University,

Emerald ash borer has caused a variety of problems all across North America.

Since its discovery, the insect has killed more than 50 million ash trees in more than 20 states and two Canadian provinces.

Denver and Fort Collins, Colorado-based Swingle Lawn, Tree & Landscape Care has offered few tips on how to treat the pest.

Landscapers should determine if ash trees are present in a client’s yard. Ash trees have compound leaves with five to 11 leaflets, branches and buds that are in pairs directly across from one another, as well as have mature bark with diamond shape ridges.

When it comes to treating ash trees, there are several factors to keep in mind such as tree size, condition and proximity to the known affected area of the emerald ash borer.

Treatment options include either an injection in the soil or the trunk or a basal bark spray (spraying the trunk).

  • Trunk Injection (Arborjet TREE-age) – Injections can start in late May through June. It is effective for at least two years; yet research has shown it can last longer. Truck injections are recommended for trees within 15 miles of the known detection site. A trunk injection may also be used if a soil injection is recommended, but the soil is not accessible.
  • Soil injection (Criterion) – Soil injections can be made mid to late spring and fall. A soil injection will protect trees for one year. Professional soil injections can place the insecticide below turf or mulch to directly reach the root zone of the tree.
  • Trunk spray or basal bark treatment (Safari) – Trunk spray is applied in June. The spray is effective for one growing season. The basal truck spray offers the advantage of being easy and quick to apply.

Ash trees have a better probability of surviving emerald ash borer if the tree has maintained a healthy status by being properly pruned, not infected by other pests and watered adequately.

The Attachments Idea Book
Landscapers use a variety of attachments for doing everything from snow removal to jobsite cleanup, and regardless of how often they are used, every landscaper has a favorite attachment.
Attachments Idea Book Cover