Help shade trees recover from July 2012 drought

Questions about this information? Contact us. September 07, 2012

Updated from an original article written by Dave Smitley, Michigan State University Extension, Department of Entomology.

Drought-stressed trees may be more susceptible to borers. Protect them by watering during dry periods and using a systemic insecticide treatment.

While driving through the Michigan State University campus and subdivisions in the Lansing, Mich., area, I am seeing quite a few dead trees that did not survive the drought. Most of these are young trees that were planted in the last three years. Their roots were not well-established, making them susceptible to drought. I am also seeing a lot of shade trees with more than half of their leaves scorched from the drought. This is going to make them more susceptible to borers and some diseases this year (2012) and next year.

You can help these trees by watering during dry periods and treating them with a systemic insecticide. One of the best sources of information on insecticides that protect shade trees from borers is the North Central IPM Center publication Insecticide Options for Protecting Ash Trees from Emerald Ash Borer, available at emeraldashborer.info.

The table below lists the products listed in that publication plus two homeowner products. Most of these products can also be used in the fall, which will help protect drought-stressed trees from borers that are active in September and October.

Product	Active ingredient	Application method	Suggested timing	For use by:
Merit	Imidacloprid	Soil drench	Mid to late spring	Professionals
Xytect	Imidacloprid	Soil drench	Mid to late spring	Professionals
Safari	Dinotefuran	Soil drench	Late spring	Professionals
IMA-jet	Imidacloprid	Trunk injection	Early May to mid-June	Professionals
Imicide	Imidacloprid	Trunk injection	Early May to mid-June	Professionals
TREE-äge	Emamectin benzoate	Trunk injection	Early May to mid-June	Professionals
Inject-A-Cide B	Bidrin	Trunk injection	Early May to mid-June	Professionals
Safari	Dinotefuran	Systemic bark spray	Early May to mid-June	Professionals
Tree and Shrub Insect Control	Imidacloprid	Soil drench	Mid to late spring	Homeowners
ACECAPS	Acephate	Trunk implant	Mid to late spring	Homeowners

For more information on how to use these products, see Insecticide Options for Protecting Ash Trees from Emerald Ash Borer.

Additional information:

MSU Extension’s Drought Resources

Dr. Smitley's work is funded in part by MSU's AgBioResearch.

This article was published by Michigan State University Extension. For more information, visit https://extension.msu.edu. To have a digest of information delivered straight to your email inbox, visit https://extension.msu.edu/newsletters. To contact an expert in your area, visit https://extension.msu.edu/experts, or call 888-MSUE4MI (888-678-3464).