Chicago Botanic Garden

YOUR GARDEN — Plant Information

Chicago Botanic Garden
Emerald Ash Borer Management Plan

Protecting Healthy Trees; Removing Others

 

HISTORY

The Chicago Botanic Garden has been monitoring its ash collection for signs of emerald ash borer (EAB) since 2004. The Garden entered into an EAB compliance agreement with the Illinois Department of Agriculture in 2007. The compliance agreement requires the Garden to take necessary precautions to minimize and control the spread of EAB. Movement of ash trees or products from ash trees is regulated under this agreement. Beginning in 2008, the Garden began using EAB-baited purple traps for summer monitoring. In December 2010, a team from the Illinois Department of Agriculture (IDA) conducted a visual inspection of the Garden's ash collection and no EAB was found. EAB was found at the Garden on two EAB-baited purple traps and confirmed by IDA in July 2011.

Ash Collection at the Garden

The Garden has a living collection consisting of more than 2.4 million plants. Its ash collection contains 463 accessioned trees representing 40 taxa. Of these, five are wild-collected specimens grown from seed procured in plant-collection expeditions in Russia.

The Garden has approximately 100 acres of woodlands that are under restoration. It is estimated that 20 percent of the trees are ash; these trees are not accessioned.

 

PHOTO: larvae
Emerald ash borer larvae		 PHOTO: emerald ash borer
Emerald ash borer

The Garden's "save" list

The Chicago Botanic Garden has selected 51 ash trees to protect from the EAB. These selected trees have received annual spring treatments of imidacloprid since 2007. The goal is to save two ash trees of each variety, ash trees grown from seed collected abroad, and some ash trees because of location and/or aesthetics.

Ash Reduction and Removals

Primarily, ash trees will be taken down on an as-needed basis once they are infested and show dieback. The trees will then be chipped (to a size that kills EAB) and the chips will be utilized on Garden grounds as mulch for planting beds. Other wood utilization is being investigated for the larger logs. No ash wood (chips/logs/stumps) will be allowed to leave the quarantine zone. Most takedown work will take place during the winter months.

Also, at annual Garden design walks of specific Garden areas, possible ash removals are discussed and approved, as a proactive measure. All four members of the EAB Planning Team participate in these walks.

In the spring of 2011, the Illinois Urban Forest Restoration Grant for Emerald Ash Borer enabled the Garden to remove 38 ash trees and replace them with diverse selections of locally grown trees.

PHOTO: ash bark

Ash bark 		PHOTO: ash bark damage

Ash bark damage

 

Please contact Plant Information Service at (847) 835-0972 or via e-mail at plantinfo@chicagobotanic.org for more information.