Help shade trees recover from July 2012 drought

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:

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

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