According to James Locke, a soil and crops consultant at the Samuel Roberts Noble Foundation, one of the best things you can do for your fencelines is to treat it early and check it often.

Woolsey cassidy
Managing Editor / Ag Proud – Idaho
Cassidy is a contributing editor to Progressive Cattle and Progressive Forage magazines.

He emphasizes that the key to protecting your fence investment is to take care of the problem before it gets out of hand.

“Once the problem balloons, it becomes much more expensive to control, and in some cases where a fenceline is completely overtaken with trees and brush, there is really no recovery; it is just a matter of taking that fence out and starting over,” Locke says.

Depending on the type and complexity of the fence, the total cost of materials and labor can be about $7,000 per mile or higher (looking at permanent fences).

When brush or unwanted vegetation grows into fencelines, it not only cuts the fence life in half, but it increases the chance those invasive species will move into your pasture or rangeland – costing you more money down the road.


Locke points out that the most problematic issues across the U.S. are typically caused by woody and brush species such as blackberry, locust, Russian olive, cedar, cottonwood and more.

In mountain areas where trees naturally occur or anywhere they are indigenous, they can grow in or near fencelines, dropping branches on the fence or stretching and breaking the wire as they grow.

If a wildfire were to spread through your pasture or rangeland, fences invaded with woody species provide a hotter fuel load and will increase the amount of heat damage on your wire and posts. But trees and brush are not the central issue in all locations.

For example, the grasslands and most areas in Texas typically don’t struggle with woody species invading their fencelines. But herbaceous plants such as the biannual and perennial thistles can be a nuisance, especially when dealing with electric fences.

Which method should you use?

There are a few different options to managing brush and unwanted plants in your fencelines: chemical, mechanical or a combination of both.

The challenge is to determine which one best fits your operation and the species you are dealing with. In most cases, controlling weeds and brush in fencelines isn’t any different from controlling it out in the pasture or rangeland, Locke says.

So to help you with your brush control, Scott Flynn, a field scientist at Dow AgroSciences, laid out some examples of individual and broadcast herbicide treatments you can use in your fenceline management.

  • Low-volume basal – Basal treatments work well for a few hundred stems per acre or when you are trying to control individual trees less than 6 inches in diameter.

    It is typically applied with a backpack hand-pump sprayer and should be applied to the lower 15 inches of the tree all the way around the trunk.

  • Cut-stump treatment – This method is useful in areas where the tree has been removed and herbicide is applied to prevent resprouting. Oil-based and water-based treatments can be used in this scenario.

    If you are using a water-based herbicide, the tree should be treated immediately rather than if you use an oil-based, which allows a little more leeway.

    Also, trees that are referred to as bleeders should have an oil-based treatment applied because the sap flow will actually push out the water-based treatment. The target area is the cambium layer or the growth ring of the tree, just under the bark.

  • Foliar treatments – Foliar treatments are sprayed directly on the plant foliage. Treatments are great in areas with a high density of trees. It can be either a spot treatment application or a broadcast application.

    All foliar applications should be made after full leaf expansion in the spring or before the leaves change colors in the fall.

Typically, if basal and stump treatments are done correctly, you won’t have to treat them again on most trees, Flynn says. But that doesn’t mean there won’t be any new growth in the treated area.

It is important that you monitor your fencelines regularly to check the treatment’s progress and for any seedlings.

“When I say correctly, I am talking about the proper timing, the proper herbicide and the proper application technique,” Flynn says. “If you have all three together, you can usually do a good job and not have to come back and treat a lot of these species.

However, on certain species, the herbicide treatment is not going to take care of itself in a year. Most likely you will have to come back next year and take care of what you didn’t get last year.

With some of these woody species, you will really have to work with them over the years to get really good control of them.”

Would the mechanical approach work better for your situation?

Locke points out that there is no blanket approach to controlling brush and trees. If you’re looking to mitigate your problem mechanically, a chainsaw or bulldozer could be an option.

Chainsaws work great in situations where there are a few large trees that need to be removed.

It is important that you are familiar with the species you are cutting down because the majority of trees across the U.S. are resprouters, he says.

It would be wise in a situation like that to use a combination of approaches to make sure there isn’t any regrowth later on.

“Seedlings are easily controlled if you get to them when they are 3 or 4 feet tall. It is a whole lot cheaper to go back through and spray them than it is to come back to a ruined fence or a bunch of trees that will need to be removed mechanically or treated with a large amount of chemicals,” Locke says. “Regular monitoring is the key.”

In one producer’s opinion

For Bruce Clark, a cow-calf producer in north-central Tennessee, controlling woody and brush species is something he knows all too well. In order to keep the cow herd out of the crops, he has to check the fenceline weekly, if not daily.

Because he manages pastures that border the woodlands, he typically can’t go a day without having to removing branches from the fences.

He has used both mechanical and chemical treatments to control both brush and tree problems. He points out that checking the fences is the easy part, but managing them after there is a problem is a little more difficult.

He recommends “catching it early because if you don’t, Mother Nature doesn’t rest; it is always growing.”  end mark

Cassidy Woolsey is a freelance writer based in Utah.

PHOTO 1: Brush growing in fencelines can create potential blind spots and stretch the wire. It is important situations like the one pictured are managed early on. Photo courtesy of Cassidy Woolsey.