The Kudzu Coalition does not patent any of its discoveries: This information is offered freely on this website, and in Coalition education activities. The United States Patent and Trademark Office is a good place to look for problem solutions, or ideas for invention. Searching on "kudzu" finds relevant patents.

One particular invention for preventing kudzu from climbing objects caught our eye, Callahan's invention for guarding against kudzu. Jack Callahan is an inventor from Cleveland, Tennessee, as pictured below during a visit with the Coalition in 2005.


The invention is based on his research, which is a major step forward for developing kudzu barriers. Barrier methods do not eliminate kudzu. They are designed to block kudzu (prevent encroachment). A barrier method prevents it from doing one, or any, of the following.

  • Climbing up a guy wire.
  • Climbing up a utility pole.
  • Crossing a fence or other barrier.
  • Invading an area that you want to protect.

Here are the main findings of Jack's research.

Callahanís patented kudzu guard devices prevent kudzu vines from climbing up guy wires and utility poles, and over fences. The Coalition's experiments and use of this invention are reported in several places on this website. See the links at the end of each section below.

Callahan's Kudzu Guard

The Kudzu Coalition has had experience with Jack Callahanís Kudzu Guard for guy wires since 2004, a commercial product based on his invention. The horizontal circumference of the guard exceeds 25 inches, as per the invention. That is, when the vines try to climb up or wrap around the slippery material, they simply slide down.

There is no question about problems resulting from kudzu vines climbing up guy wires to the top of utility poles. During the dormant season the vines produce a "rats nest" look that is just plain ugly. During the growing season, some might say that the green foliage high on a pole or wire is attractive. We disagree.

We have been told that kudzu does not interfere with power distribution when it is dry. And we have also been told that when it rains, the conductivity goes up and this can cause power outages. We have seen no figures on how often this kind of kudzu-caused outage occurs.

The Coalition has studied Jack Callahanís patent and have talked with him at length. Jack's conclusions are borne out by what actually happens in the kudzu patch. When his guards are properly installed, they do perform as intended. We enthusiastically encourage use of the Callahan Kudzu Guards in and around Spartanburg. Here is an example of before and after photographs. Besides the guy wire guards, note the black guard wrapped around the pole, another product derived from the Callahan patent. June 2004.

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The Coalition has put up several dozen Callahan Kudzu Guards for purposes of learning, demonstration, and eyesore removal. There were some early, small disappointments, but these were resolved in 2005. For example, the early instructions for the single guy wire guard advised the user to install it "as close to the ground as practical." This is flat out incorrect. Typically the top of the kudzu mass will be two to three feet high. Where this occurs, the Kudzu Guard should be placed higher on the guy wire to ensure a 3½ foot clearance above the top of the kudzu mass. Those who read Jack Callahan's patent will understand that kudzu vines can "reach" up or out about 42 inches from the top of the mass. Osmose Utilities Services Inc., the original manufacturer of the Callahan Kudzu Guards, completely revised their installation instructions accordingly.

Originally the Kudzu Guards did not include a wire clamp, nor did the instructions explain the need for such a clamp to support the guard on the guy wire; that is, to keep the guard from sliding down the wire. We bought several dozen clamps at the local hardware store. A height adjustment clamp to go onto the guy wire began to be included in each guard package.

The first production run of the Kudzu Guard was made from polyvinylchloride (PVC). The later formulation used polyethylene, which makes it more resilient and better able to withstand cold and heat extremes. The manufacturer also began using a thicker sheet to improve the wear and tear properties.

The Coalition continues to have good results with the reformulated guards. We work closely with the local utility company manager because utility companies do not want customers disturbing or altering their utility poles and guy wires. Most people are intrigued about bringing technology such as Callahan's Kudzu Guard to the fight against kudzu. It is good to have Jack Callahan's technology for providing a barrier to kudzu vines, and we are glad to have bought and used them. Our first installations were just for testing, but now we use them to protect guy wires as a standard practice.

Jack Callahan visited the Coalition January 2007, and demonstrated an improved version of the Callahan Kudzu Guard. It uses an air permeable mesh textile to reduce the effects of strong winds on the guard. In the first photograph Jack (right) shows Coalition volunteer Paul Savko (left) how it installs on the guard frame. In the second photograph are volunteers Steve Patton, Jack, Paul, and independent contractor Johnny Robinson, who the Coalition has trained to kill and control kudzu without chemicals.

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We were very pleased with the Osmose response to each of our suggestions. Regrettably, as of May 2007, Osmose no longer manufactures the guards.

See also Coalition guard work.

Callahan's Kudzu Barrier Fence

Jack's fence barrier builds on Callahanís finding and patent that kudzuís maximum "reach" is 3½ feet above the supporting kudzu mass. The barrier uses two sheets: A vertical sheet (first photograph) that is a barrier to climbing kudzu; and, an optional horizontal sheet (second photograph) with two purposes. First, the horizontal sheet prevents kudzu from growing up from the ground near the fence. In this case kudzu would pile up against the fence, and eventually grow over it. Second, the horizontal sheet prevents tall invasive plants from creating a kudzu scaffold up against the fence (on the kudzu side of the fence), or growing over and down into a kudzu patch as a bridge over the fence for kudzu. The horizontal sheet is placed on either side of the fence, both sides, or is not used whenever it is unnecessary. A decorative fence is used with the invention in the example shown. Both photographs are courtesy of Jack Callahan, June 2002.

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In the next example the invention is used to keep kudzu away from a vertical structure (tower) at a TVA site in Blue Ridge, Georgia. Note in the first photograph that a small portion the horizontal sheet is seen at the left outside of the barrier fence. Thirty day later (right photograph) kudzu is still well below the top of the fence. Both photographs are courtesy of Jack Callahan, July and August 2005.

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See also Coalition fence work.

Callahan's Kudzu Tree Shelter

Here is another aspect of Jack's invention, a barrier that acts as a kudzu shelter for trees. The mesh material passes light and air to the growing tree, and reduces air resistance. Before (June 2005) and after (October 2005) installation of Callahan Tree Shelter, tested without a tree: Kudzu does not grow up the barrier after four months.

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Here are photographs of a later design of the tree shelter. June 2006.

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See also Coalition tree barrier work.

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