Tough weeds? No effective herbicide options? Let MSU Extension know!

Bill Lindberg<lindbe35@msu.edu>, Michigan State University Extension and Debalina Saha<sahadeb2@msu.edu>, Michigan State University Department of Horticulture - August 20, 2025

Input from Christmas tree growers can influence future herbicide labeling decisions.

Rows of newly planted Christmas tree seedlings in a field. Each small tree is surrounded by a circle of mulch to reduce weed competition. The soil appears damp, and the background shows more rows of young trees near a wooded edge. — Photo 1. A combination of chemical and non-chemical control methods results in superior weed control. Photo by Bill Lindberg, MSU Extension.

Weed management is often one of the most important challenges in Christmas tree production. Weeds can compete with Christmas trees for water, nutrients, space and sunlight. If weeds are not well controlled, it can cause significant reductions in Christmas tree growth, quality and survivability. A combination of non-chemical (mowing/wood chips) and chemical control (pre- and post-emergent) methods results in superior weed control (Photo 1). However, some weeds currently have few or no effective labeled chemical control products for Christmas tree production (Photo 2).

Christmas tree field with young evergreen trees heavily surrounded by tall, dense horsenettle weeds. The weeds have broad leaves, small flowers, and green berries, crowding the trees and competing for space and resources. — Photo 2. Christmas tree field with large infestation of horsenettle. Photo by Bill Lindberg, MSU Extension.

To address these challenges, Debalina Saha, PhD, is leading a research group with the goal of adding “Christmas trees” to the label of more herbicide products through the IR-4 Environmental Horticulture Program. How can you help? Michigan State University Extension is asking Christmas tree growers to complete the 2025 Grower & Extension Needs Survey to inform the IR-4 Environmental Horticulture Program weed science research group on what weed species you struggle with in relation to having no or few herbicide control options.

The survey deadline is Aug. 29.

Start Survey

Further questions on this subject or survey can be directed to Bill Lindberg at lindbe35@msu.edu or Debalina Saha at sahadeb2@msu.edu.

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).