• There are a variety of different herbicide application methods that can be used to control overgrown vegetation.overgrown bench image by Watt from Fotolia.com
  
  In certain environments it may be necessary to use herbicides to control the growth of undesirable plants. There are a few different application techniques depending on the types of plants being controlled. Herbicides can be sprayed directly on the foliage of the plants, applied to cut sections of the plant’s trunk or applied over the bark of a woody vine or small tree.
  
  

Foliar Application

• While the plant is in season and bearing leaves, herbicide can be applied directly to the foliage, or leaves. The herbicide is generally applied using a backpack sprayer with a flat or cone-shaped tip adjusted so that the flow rate is low and easy to control. The sprayer should be adjusted to distribute herbicide at a rate between 20 and 50 pounds per square inch (psi). In high traffic areas cordon off the section being sprayed to prevent humans from being exposed to the toxic herbicide.
  
  

Cut Surface Applications

• Cut surface applications involve cutting the plant and then spraying the herbicide onto the cut wood. An axe is used to make cuts along the base of the plant’s stem in the “hack and squirt” method. A series of cuts are made at a downward angle through the exterior bark of the plant and into the sapwood. These cuts can be made in a series of hacks from the base of the stem or in a continuous cut around the circumference of the plant’s stem. A backpack sprayer is used to apply the herbicide to the cut sections of wood. The “cut stump" method involves cutting down the plant using your backpack sprayer to apply herbicide to the cut stump.
  
  For each method use your backpack sprayer adjusted to a low pressure, between 20 and 40 psi; and adjust the tip to provide a narrow, controllable spray pattern. The cut surface applications provide greater control and use less herbicide than applying to the foliage. Also, cut surface treatments can be used during the winter months when the foliage has dropped, as long as the ground is not frozen.
  
  

Basal Bark Application

• With the basal bark method the herbicide is sprayed directly on the woody vine or tree’s bark to the point of saturation. The herbicide can be applied to one side of the stem if the trunk diameter is less than 3 inches. Within the hour the applied herbicide will spread from one side of the stem to the other. For thicker trunks measuring 3 inches or greater, apply the herbicide to both sides of the trunk. Use a backpack sprayer with the pressure adjusted to between 20 and 40 psi, and adjust the tip to provide a narrow spray pattern that can be easily controlled.