However, many are still lying dormant and will be controlled by preemergence herbicides. Applications of preemergence herbicides are useful in many sites landscape beds containing trees and shrubs, tree rings, perennial plantings, annual flower beds, and in mulched and graveled areas. Be sure the type of site to which you wish to apply the herbicide is listed on the product label. Future planting areas and flower beds should not be treated until or preferably after planting. First, no single preemergence herbicide will control all germinating weed seeds.
Product labels list the weed species the product has been shown to control.
Consult previous scouting notes to determine if one weed is particularly problematic, and be sure the product you choose will control it. Second, herbicide labels list the landscape plants that the product can safely be applied over. If a particular plant is not on the list, damage could occur if that plant comes into contact with the herbicide. New plant species are added to most product labels each year, so check them carefully. Products with a broader spectrum of weed control and an extensive list of ornamental plants on their labels include Preen, Pendulum, Ronstar, and Surflan.