Herbicide Selectivity in Invasive Plant Management

Choosing the right herbicide to fit your vegetation management objectives is an important decision. Herbicides are classified in a number of ways based on how they are used and their selectivity on different plant families. 

NONSELECTIVE HERBICIDES are not selective about the plants they control. Glyphosate (Roundup*, Accord® XRT II, Rodeo®, and other trade names) is a non-selective herbicide that will cause significant injury to both broadleaf and grass plants. Often undesirable weedy plants will re-establish in bare ground created by nonselective herbicide treatments. 

SELECTIVE HERBICIDES are those formulated to control specific plant families. Milestone® and Transline® are selective herbicides that control invasive broadleaf plants, allowing grasses and some desirable broadleaf plants to thrive. Applying selective herbicides to target plants reduces the potential for erosion by maintaining vegetative cover and minimizes damage to desirable non-target plants.

Remember that many herbicides work selectively within a given rate of application. Too low of a rate and the target plant is not controlled, and too high of a rate and injury to non-target (desirable plants) may occur. Selectivity is a dynamic process that involves the interaction of the plant, the herbicide, application methods and rates, and the environment.

Nonselective herbicide (glyphosate) applied to Scotch broom (Cytisus scoparius) resulted in injury to desirable grasses (left) shown 45 days following application.  Removal of grass competition by glyphosate allowed for invasion of oxeye daisy  (Leucanthemum vulgare), another invasive plant, 416 days after application (right).

®™Trademark of The Dow Chemical Company (“Dow”) or an affiliated company of Dow. Milestone is not registered for sale or use in all states. Contact your state pesticide regulatory agency to determine if a product is registered for sale or use in your state. Label precautions apply to forage treated with Milestone and to manure from animals that have consumed treated forage within the last three days. Consult the label for full details. State restrictions on the sale and use of Transline and Accord XRT II apply. Consult the label before purchase or use for full details. Always read and follow label instructions. 

*Trademark of Monsanto Technology LLC. 

Active ingredients for herbicide products mentioned in this article: Milestone (aminopyralid), Transline (clopyralid), Roundup, Accord XRT II, Rodeo (glyphosate).