How to Kill a Tree or Woody Stem Plants

Cut the tree close to the ground and make the stump as level as possible. This will keep herbicides from running off. The University of Florida Extension recommends the use of glyphosate, triclopyr ester or triclopyr amine.

Apply herbicide to a stump immediately after cutting for best effect. All recommended herbicides are sold under different trade names.

To kill larger trees, with trunk diameters of over 5 inches, it is important to get the chemical in the vascular system of the tree. Make cuts around the trees in the bark using an axe and apply chemical into the cuts. Do not apply herbicides at the time when sap is flowing from a tree as this will dilute the herbicide.

You can also make injections of herbicide into trunk cuts using specialized equipment. For injecting herbicides, make cuts every 2 to 6 inches, as recommended by the Washington State University Extension.

Spray foliage of woody plants to kill plants up to the height of 15 feet. Avoid chemical application on very hot days or on plants that are drought stressed. Recommended timing, according to Washington State University Extension, is between early summer to September.

Cover entire plant canopy, but do not spray so much that the herbicide will start running off the plant. Avoid when there are chances of rain, as this will wash off the herbicide.

Re-treat woody plants with herbicide when new and fully expanded leaves start to appear. Generally this takes anywhere between six and 18 months after the first spray.