Herbicide Toxicity to Landscape Trees and Shrubs

Jan 28 2019 - 11:00am

The herbicide products available today to homeowners and professionals alike are more varied than ever before. Yet there is some commonality among some of the most popular, marketed products. Herbicide labels are notoriously vague, and as a consequence, these products are becoming more damaging and deadly to non-target plants than ever before. Some herbicides will move from the point of application while others will not. Some herbicides are systemic while others are not.

This session will examine the symptoms of herbicide injury on trees and shrubs, ranging from mild to wild. Tips for diagnosing herbicide injury in the landscape along with clues for guidance on the prognosis for plant health and potential recovery will be discussed.

Session Track: 
Turf & Landscape Management


The Plant Doctor, LLC

Dr. Roberts retired from Michigan State University in 2018 after committing four decades to advancing MSU’s Land Grant Mission, originally signed into law by President Abraham Lincoln during the midst of the American Civil War. He has published hundreds of articles and has taught hundreds of lectures and workshops.

Dr. Roberts has researched many issues in Michigan’s plant industry, including Oak Wilt, Dutch Elm Disease, Diplodia Tip Blight of Pines, along with variety of cultural problems such as plant nutrition and herbicide toxicity. During his career, he has discovered a variety of new diseases and pests such as Phomopsis Canker of Spruce and the first bacterial wilt disease of turfgrasses in North America.

In the early 2000s, his research on Ash Decline in Southeast Michigan led to the discovery of the invasive Emerald Ash Borer in North America.

In his retirement, Dr. Roberts intends to remain active with the Arboriculture/Landscape/Nursery industries. Dr. Roberts is President, CEO and CBW (Chief Bottle Washer) of The Plant Doctor, LLC…aka The Tree Doctor. His contact information remains the same: Phone (248) 320-7124; Email robertsd@msu.edu