There are some pre-emergence herbicides, such as Treflan, that need to be incorporated into the soil before the trees are planted. You will also need to take into consideration the fact that some herbicides, such as Princep, should not be used in sandy or alkaline soils. It is generally recommended that you have your soil tested if you do not know the texture, organic matter content or pH of the soil. Additionally, the proper calibration of your spray equipment is important to ensure an accurate and uniform herbicide application. Applying the right herbicide at the proper rate is important if you want to keep your costs down and avoid injury to your trees.
Herbicides are especially dangerous when improperly handled, applied or disposed of.
They can cause injury to desirable plants, wildlife and fish, and they can contaminate water supplies. Always read and follow the directions on the herbicide label and follow all precautionary statements. It is a violation of federal laws to use any pesticide in a way that is inconsistent with its label. The label will list the tree and shrub species on which it can be used, the weed species it will control, recommended application rates, timing of applications, disposal and other directions and precautions. Pennant is labeled for weed control in field-grown ornamentals.