Herbicide Drift

One of the most common questions during the summer months, especially in a hot, dry summer, is, “Why are my (insert plant) leaves all twisted and curled?” Herbicide drift injury happens far too often, with the saddest part being that this issue is usually preventable and, in some cases, not caused by the homeowner. Unfortunately, as shown in the picture on the left, many of our bedding and vegetable plants are very sensitive to herbicides, and it doesn’t take much time to cause damage.

Various factors, including temperature, wind speed, and improper spraying practices, can cause herbicide drift. It’s best to spray when wind speeds are below 10 mph but not completely still (no airflow can make things worse) and when the temperature is below 80 degrees. Several typical lawn and weed killer products contain 2,4-D, which can volatilize at warm temperatures before it dries and spread to where we don’t want it. Always check the weather and read the label before applying any chemical to ensure you use it safely.

Luckily, unless a tree or shrub is stressed or gets a hefty dose of herbicide, most trees and shrubs will survive some herbicide drift. On the other hand, annuals and other herbaceous plants can easily be killed or severely stunted by drift. Once a vegetable has been hit with an herbicide, it’s ultimately up to the homeowner to decide if they want to eat the produce. There is little information on how much chemical moves into the fruit from the leaves. It’s best to prevent drift when possible and replant if you can.

Have questions? Contact our office where our Horticulture Extension Agent will assist you with questions.

Phone: (316) 321-9660

Email: callae@ksu.edu