Mesquite: getting it under control in 5 proven steps

Mesquite trees are the most popular “trash” tree out there. Though mostly that popularity is due to the excellent bbq wood that it provides. Despite it being able to provide us with some really good firewood it does pose some problems for range managers.

Now do not completely get me wrong on this. Despite being viewed by some as a poor-quality rangeland plant mesquite does have some benefits. One such benefit is that it can provide both food and cover for both wildlife and livestock. Also, since it is classified as a legume it has the ability to fix nitrogen back into the soil.

Despite its benefits listed above if it is left unmanaged it can very easily dominate rangeland. In the process of doing that, it will choke out any grass that you may have in the pasture. What that means is that there will be less for your animals to eat. With it also being a very thirsty plant it will also suck your place dry if you let it get out of hand.

I do feel that a disclaimer is needed here so the thing to remember is that complete eradication is unlikely, not to mention unnecessary, but getting them under control is possible. here are 5 steps that you can follow to get better control of your pastures.

Step 1: Determine Mesquite cover

The number of trees that you have in a pasture will determine which control method is best for you. If you have a very light amount you could get away with some light chemical or manual control. However, if the cover is very thick some heavy chemical or even mechanical control may be necessary.  If mechanical is the only option it will get very expensive so it is best to know beforehand.

If there are more than 400 trees per acre a broadcast method such as aerial spraying will probably be the most cost- and time-effective for you. Depending on the thickness multiple aerial spraying will probably be necessary. Also, even though you sprayed you may have to still go in and remove some of them by hand to really get it going.

The 2 methods of measuring tree density:

1. Measure off at least 4 square areas that are 66ft by 66ft. Count the number of mesquite trees in all of those areas that you made. Once you have the count average the number of trees per square. Once you are done multiply by 10 to get an estimate of the density.
2. Walk at least 4 lines that are about 363ft in the pasture that you want to measure. In order to keep them in a somewhat straight line have the lines going towards some type of landmark for you to walk to. Once you have walked it the first time turn around and walk back in the same line. As you are doing that count every mesquite tree within 3ft of your path. Then when you have the count from the 4 lines figure out the average to give you a manageable number. Finally what you will do is take that average and then multiply it by 20.

I know this goes without saying but with either option you go with be sure that the different areas you will be counting are in different areas of the pasture you are wanting to control. This will give you a more overall number than just counting in one particular area. Now, on to step 2.

Step 2: Select your control method

Now that you have determined the number of trees that you are wanting to control it is time for the next step. Here you will pick which type of control method you will be going with.

There are a few methods that you can use to control mesquite: the foliar-spray method, the stem-spray method, and the mechanical method. Now you may be thinking that doing a control burn could be an option but in most cases that is not the way to go. The problem with using fire is that most of the time it will not completely kill the root bud which is what you are wanting to kill in order to kill the tree.

Each method has its pros and cons so it is best to weigh the options and go with the one that works best for you and your pocketbook.

  Mechanical

As the name implies this means getting rid of the plant by mechanical means. This can be with a dozer, skid steer, or tractor (whichever works for you).

The problem with this is what I mentioned above: just removing the top will not get rid of it. A root grubber or something similar will have to be used in order to remove the roots and buds so they will not return. If you don’t kill the whole plant then you can expect in about 5 years the plant will completely return.

The main drawback to using this method is that it can get expensive really quickly. In fact, the price can get high enough to where it will be like you are buying the land all over again. Diesel fuel is not cheap after all.

Another downside is that when you are moving the piles of mesquite around they will be dropping the beans which means will also be reseeding the pasture for the next go-round.

  Stem spraying

This method means that you will be spraying a chemical around the trunk of the mesquite tree. This method works best on young trees with few basal stems. If it has several of them then the chemical will not be as effective and thus less economical in the end.

Stem spraying can be done year-round but its best results will be during the spring-summer growing season. This is when the plant is doing its most growth and will absorb the chemical better. The main factor in using this method is the size of the plant. To be effective the plant should be smooth-barked and no bigger than 4 inches in diameter.

A mixture of Remedy and diesel fuel is the preferred method of doing this. The diesel will act as a coating agent to make sure that it stays on the plant and is absorbed. The concentration of Remedy that you will use depends on the size and age of the plant. Usually, it will require between 15% and 25% of chemicals.

To apply the chemical you will first make sure that your nozzle is adjusted to deliver a narrow, cone-shaped mist. I discuss the steps you need to take to make sure that your sprayer is working properly here.

Now that your sprayer is set hold the nozzle within 1 to 2 inches from the mesquite stem. You will then spray the mixture all around the trunk from the base to 12 inches up. As you are applying the chemical wet the trunk almost to the point of runoff.

  Leaf Spray Method

This method works best on mesquites that are brushy and have many stems growing from ground level. It is also best that they are not taller than 8ft.

The best time to use this method is in the late spring (May-June) when the leaves on the plant have changed color from a light-pea green to a more uniform dark green.

A mixture of 1/2% Reclaim, 1/2% Remedy, and water is recommended for this method. You will also want to add a surfactant or dish soap to make sure that it will stick to the leaves long enough to be absorbed. Another thing that you can add is a type of marker dye to the mix to identify which plants have already had an application.

Step 3: Select the correct stage of the mesquite life cycle

If you decided to go with a foliar-spray method then this step is very important. The mechanical and stem-spray methods can really be used year-round.

The life cycle typically begins with the tree’s bud break during the spring. It will usually start in the south and work its way north as the weather warms up.

Twigs and leaves will begin to grow when the soil temps reach 65 to 75 deg F. This stage usually lasts for about 6 weeks depending on the weather.

45 days after bud break and when the soil temp 12″ below the surface reaches 75deg F it begins to replenish the carbohydrates in its root system. This stage is shown when there is no new twig growth and the leaves have a dark-green color to them. It is during this time that the foliar-spray method will be the most effective.

Step 4: Use your mesquite control plan

As you may have guessed this is the “action” part of the steps. This is where you go out and either spray or grub the trees in your pasture.

If you will be applying chemicals be sure to use the correct amount of herbicide. Too little herbicide will not be effective while too much of it can damage the environment. The Texas AgriLife Extension service has many resources available to help you in this matter.

Make sure you remove the root bud if you’re going the mechanical route. This will ensure that you will kill the plant and not have to go over it again.

Step 5: Repeat

Unfortunately controlling mesquite is not a “one-and-done” kind of process. You will always have to go out and either spray or mechanically remove trees. It will take many years for you to get them into the stage of control that you are looking for.

Even if you have them under control you may still have to re-treat the area every 5 to 7 years. It is generally easier to spray the younger trees in order to prevent new growth from occurring.

Some other control ideas you can use are:

• Don’t graze a pasture that produces a lot of seeds
• Fence off areas with high mesquite seed production
• Confine your livestock 3 to 6 days after they have been in a pasture with a lot of mesquite beans to reduce the chance of carrying them to different areas
• Leave adequate grass to grow in order to discourage the seedling establishment