Weed killers or herbicides are chemicals designed to kill woody and/or herbaceous plants. Weed killers can be classified as preemergence, postemergence, contact and soil sterilants.
The three most common injury symptoms are:
- hormone effect, when foliage take on a grotesque or gnarled, twisted appearance.
- root inhibitor, where severe root pruning results in a dieback of top growth, and
- chlorophyll inhibition which causes foliage to turn white to pinkish white.
Most herbicide injury can be prevented merely by following label directions. Mixtures of fertilizers and herbicides should be used with extreme caution around the home landscape. If problems are found and herbicide injury suspected, specimens and/or inquiries should be sent to the weed control specialists with the Texas AgriLife Extension Service.