How to...

August 2001

The following information has been compiled to provide suggestions about controlling undesirable woody plants, generally termed "brush," around the landscape with herbicides. In hunterdon County the most common problems are poison ivy and multiflora rose, but there are any number of other woody plants that may be weeds under certain circumstances. The challenge for the property owner is to control the undesirable plants without damaging or killing desirable plants.

From WEED CONTROL AROUND THE HOME GROUNDS, by Stephen E.Hart, Darren W. Lycan and John A. Meade, Assistant Extension Specialist, Program Associate and Emeritus Extension Specialist, Rutgers Cooperative Extension.

Many people move into new homes with recently cleared woods and discover later that weeds such as poison ivy, brambles and other vies and brush species are infesting areas around the home grounds.

There are several herbicides that can be utilized to clean up these problems for woody species such as poison ivy and honeysuckle as well as more tender plants such as brambles and Japanese bamboo Roundup (glyphosate) herbicide is suggested. Apply in the late spring after leaves have fully opened or in late summer/early fall prior to leaf drop. Roundup herbicide will kill desired plants if sprayed on their foliage. if poison ivy is growing in and around desired plants such as a hedge pull the poison ivy away from the hedge (do not pull the poison ivy out of the ground), lay it on the ground, and then spray the leaves with Roundup. Place several layers of newspaper under the poison ivy to prevent injury to any desired grasses. Allow the treated poison ivy to remain attached to the soil for 5 to 7 days so the Roundup can traslocate into the root system. On small infestations the Roundup solution can be brushed or sponged onto individual leaves. Be sure to treat as many leaves as possible.

When poison ivy is growing up trees, cut the vines at head height and allow the upper portion to die. Treat the lower portion with a herbicide specific for poison ivy (commonly available at a home improvement store or garden center) after the new leaves are fully expanded. In ten days remove the growth.

Free standing brush can be removed in several ways. The foliage can be treated with a herbicide specific for brush control (these herbicides generally contain the active ingredients 2,4-D or triclopyr) in the summer or the brush can be cut leaving a 12 inch stump. Immediately after cutting, threat the stump with a full strength Roundup solution or a herbicide specific for brush control. For maximum effectiveness perform this operation in the fall and if a brush herbicide is used apply fuel oil or kerosene.


Methods of application for brush control (check product label for proper use).

  1. Foliar Treatments. The herbicide is sprayed on the leaves of the brush during the growth season. The herbicide then moves throughout the plant as well as into the root system and kills the entire plant. This is one of our most effective types of treatments but it does lead to unsightly brownout of the foliage which is often times undesirable. It is effective only for low growing shrubs and small trees where the spray can hit the entire plant.
  2. Basal Treatments. The herbicide is diluted with penetrants such as kerosene, fuel oil, and/or one of the commercial penetrants sold under many trade names. The concentration in this type of application is much higher than that in the foliar sprays. the material is applied to the bottom 12 inches of the stem and penetrates the bark. Allow a small amount to run onto the ground. This treatment can be applied almost any time of year but it most effective when applied in the fall or early spring. In this way you avoid the brownout of the foliage. The chemicals used here are the same as used for the foliar application but at different concentrations and with a different type of carrier. An important aspect of this treatment is that it requires thorough treatment of the stems. This treatment is most effective for bush up to 5 inches in diameter. For large rees it would be well to modify this to include the "frill" treatment. By using an axe or hatchet, a piece of the park is rolled out and the herbicide is place in the frill. Several cuts should be made around the tree. There are commercial applicators available for this type of treatments. One consists of a hatchet with a hole in the blade. The frill is made and the herbicide applied at the same time.
  3. Cut-stump. This is designed to eliminate the re growth of brush removed by cutting. The herbicide is mixed with the penetrants and applied to the top of the stump and allowed to run down the side of the stump. Some labels call for more precise treatment wherein the herbicide is applied only to the conducting tissue of the stump. A dye in the spray solution helps pinpoint the application. The time of the year for this treatment is not too important. It is important that the herbicides be applied as soon as possible after cutting. Good results have been obtained event with a heavy quantity of sap flow from the cut stump.

    These treatments if properly applied allow the use of minimal amounts of herbicide introduced into the environment.