Integrated Pest Management

Herbicide Damage

herbicide damage

Herbicide damage (Ryan Davis, Utah State University Extension)

herbicide damage

Herbicide damage on spruce (Jason Sharman, Vitalitree, Bugwood.org)

 

Description

Herbicides are designed to kill plants. Misuse, volatilization, drift or root uptake of herbicides can cause wide-ranging deformities in plants, leaf and branch dieback and plant death. Signs of herbicide damage include leaf deformation, twisting, cupping, yellowing, wilting, browning, scorching, brown spotting/speckling, narrowing, strapping and dieback. 

Management

When using herbicides, always follow the labeled directions. Calibrate the sprayer before applying any herbicide and avoid applying when it is windy. Herbicides can drift even in the slightest breeze. If breezy, use lower sprayer pressure to produce coarse spray droplets. Keep the spray nozzle close to the ground and spray only the targeted area. Spray when the air temperature is below 80F. Homeowners should not use soil sterilants or long-term vegetation control chemicals. Never use herbicide spray equipment to apply insecticides or fungicides.