This publication does not present all of the information you need to make a selection. Carefully read the labels of promising herbicides before purchasing and applying any herbicide. Herbicides are either preemergence, applied before weed seeds germinate, or postemergence, applied after weed seeds germinate. Preemergence herbicides are soil-applied and control weeds by inhibiting seed germination and seedling development. Postemergence herbicides are generally applied to the foliage of established weeds to be absorbed and translocated.
Some herbicides persist in the soil and control all stages of plant growth.
These chemicals may be nonselective and should not be used near trees or shrubs. Select a herbicide with specific label directions for use on the kinds of trees or shrubs in your planting. An herbicide recommended for one kind of plant may not be safe for another kind. The age of the trees and shrubs and how long they have been planted should also be considered. The choice between pre- and postemergence herbicides depends on the presence or absence of vegetation.