University of Maryland Extension

Herbicide Damage - Trees and Shrubs

herbicide damage

Herbicides are products designed to kill undesirable weeds, however, misapplied herbicides can cause injury to desirable landscape plantings. Symptoms of herbicide injury often involve discolored or distorted leaves and can easily be confused with other cultural or environmental problems, as well as insect, mite, disease problems and other pesticide injuries. Diagnosis is often difficult because information about specific symptoms on ornamentals is limited. In addition, the dose received by the plant and how it was applied will often influence symptom expression. Some herbicides are more readily absorbed through plant roots while others are only absorbed through leaf and stem tissue. Tissue and soil analysis for herbicide residues is often not available, impractical or very costly.
Symptoms of some commonly misapplied herbicides:

  • 2,4-D and MCPP: Twisted and bent shoots and petioles
  • Dicamba: Dwarfed, distorted and/ or discolored foliage
  • Glyphosate: Plants stop growing, remain green for several days, may develop yellow leaves, then turn to uniform brown. Plants treated in the fall may not show symptoms until the following spring. Leaves on new growth may develop abnormally, with a stunted, narrow or closely packed appearance, called witches-brooming.
  • Trifluralin: Roots may be swollen or club-shaped, roots may appear shortened with fewer secondary roots present.

herbicide damage yew
Herbicide damaged yew

herbicide damage on pine
Needle damage on white pine

herbicide damage on evergreen needlesherbicide damage on needles
Two examples of amitrol damage

leaf distortion caused from herbicide
Herbicide injury causing distortion

herbicide damage on rose
Glyphosate injury to rose

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