A Food Plotter’s Guide to Herbicides

Proper use of herbicides can help prevent weed growth in food plots, resulting in more high-quality food for whitetails.

A Food Plotter’s Guide to Herbicides

A clean, weed-free food plot is not only more satisfying to you, it’s more attractive to the deer you hope to feed. Herbicides can help create a nearly weed-free plot.

There is no way around it: You cannot grow a vibrant, lush, weed-free food plot without the use of chemicals. Sure, you can disk new ground enough to kill most existing plant growth. You can mow annual weeds to prevent them from seeding. But aside from hand-pulling perennial weeds and those annuals that grow close to the ground, you will still have a healthy crop of weeds clogging up your plots. Weeds rob your food plots of space, nutrients, moisture and sunlight. They have to go.

Herbicides are a necessary part of the food plot equation. Some kill every plant they touch, others only kill specific types of plants and some prevent new weeds from sprouting. When used properly, herbicides are not only effective, but safe, too.

Selective and Non-Selective

“Non-selective” or “broad spectrum” herbicides are just that. They kill virtually every plant they touch. Selective herbicides affect only certain types of plants — grasses, for example, or broadleafs.

The most common broadleaf herbicide is 2,4-D, which is available under a wide variety of brand names. It is widely used on lawns to control weeds, but it is a good product for grass-specific food plots like wheat, oats, sorghum and corn.

Some are even more selective. 2,4-DB, also known as butyrac, will kill most broadleaf plants, but it won’t kill legumes such as clover or alfalfa. And like 2,4-D, it won’t kill grasses, either. That means it is a great choice in a blend of clovers and such things as oats or wheat.

Be careful, though. Many of the plants we grow for deer are members of the grass family and will die if they are exposed to grass-specific herbicides such as sethoxydim — the active ingredient in Poast — or clethodim — the active ingredient in such products as Arrow and Whitetail Institute’s Arrest Max. Corn, sorghum, wheat and oats are all grasses. However, if your plot consists of broadleafs such as clover, brassicas or chicory, and grass competition is a problem, either of the two grass-selective herbicides will work fine. Clethodim-based products tend to cost less.

However, neither chemical will kill tall fescue, one of the most problematic and persistent grasses. Fescue must be controlled with a non-selective herbicide such as glyphosate, the active ingredient in Roundup. In fact, glyphosate is the most widely used herbicide in the world and it is a vital tool for food plotters and land managers. It kills plants dead without any residual impact. In other words, it doesn’t linger in the soil.

Thanks to genetic modification, some crops that deer love are actually resistant to the effects of glyphosate. Known as Roundup-ready, such things as corn, soybeans and even canola (a member of the brassica family) can be over-sprayed with Roundup without harming those plants. It will kill other plants, though, leaving the plot virtually weed-free.

In addition to selling a wide variety of seed blends, some food plot companies also sell herbicides. For example, Whitetail Institute offers Arrest Max, a selective grass herbicide that will control most grasses without harming clover (photo above).
In addition to selling a wide variety of seed blends, some food plot companies also sell herbicides. For example, Whitetail Institute offers Arrest Max, a selective grass herbicide that will control most grasses without harming clover (photo above).

What About Trees?

Herbicides aren’t just a necessary tool for clean, healthy food plots. They can be a great way to remove and control a variety of unwanted plant growth throughout your land. In most cases, glyphosate is a good all-purpose herbicide for killing most unwanted plants. Fescue, tree-of-heaven, sericea lespedeza and multiflora rose can all be knocked back with a dose of glyphosate. In some cases, a second round might be needed.

However, tough, woody shrubs and trees might call for a more aggressive herbicide. Some trees — sweetgums, for example — can be tough to kill with even full-concentrate glyphosate. So can Chinese privet, a highly invasive, non-native shrub that is difficult to control with glyphosate.

A good alternative herbicide for those types of plants is imazapyr. It works through the soil and is absorbed by the plant’s roots instead of through the leaves like most herbicides.

Imazapyr is also a great tool for preventing tree stumps from sprouting. A common application method is to paint the outer edge of the freshly cut stump with the herbicide.

Weeds are tough to beat, but using the right herbicides can help reduce weed competition in any food plot.
Weeds are tough to beat, but using the right herbicides can help reduce weed competition in any food plot.

Restricted or Non-Restricted

Not all herbicides are available to the public. These restricted-use herbicides require a permit to purchase and use. Obtaining those permits can require an exam in some states, while others just ask for a completed form.

Generally, no food plotter needs a restricted-use product such as atrazine, a common herbicide used as a pre- and post-emergent on various grasses in the turf industry. A number of other restricted-use herbicides are highly specialized, as well, and aren’t necessary for growing and maintaining food plots. In other words, stick with common products available over the counter.

Pre- or Post-Emergent

Some herbicides are applied immediately after the seeds are planted and before those seeds sprout. Pre-emergents work by killing some seeds soon after they sprout while allowing others to sprout and grow. They are often plant-specific, so it is important to know which ones won’t grow and which ones will with that herbicide. And many work only on one type of plant, corn or beans, for example.

Post-emergents, on the other hand, work on plants that are already growing. The plant absorbs the chemical into its system and carries it down to the roots, killing the entire plant.

Pre-emergents can have place in food plotting, particularly in established perennial plots. With some exceptions, they won’t harm plants that are already growing so they can prevent a new crop of weeds from sprouting and taking over your existing plots. They can also be an option for new single-plant plots such as corn, beans or wheat. Generally, though, post-emergent herbicides will do everything you want. The only difference? You’ll have to wait until the undesirable plants are growing before you can treat them.

Surfactants

No matter what post-emergent herbicide you use, it should be used in conjunction with a surfactant, an additive that helps increase the herbicide’s performance. In some cases, they are a mandatory addition. Your herbicide won’t work nearly as well without a surfactant.

A few herbicides, including most store-bought glyphosate-based products, have a surfactant already added. Many other herbicides don’t. In many cases, you’ll need to add one to your tank before you spray.

Surfactants help spread the droplets of water than land on plants. In most instances, herbicides are absorbed through the plant’s leaf. By spreading out the liquid across the entire leaf, more herbicide will be absorbed into the plant and down into the roots.

There are several types of surfactants, but you need to buy only one, a non-ionic surfactant. A good all-purpose product can boost the performance of any herbicide. They are inexpensive, too. Crop-oil-concentrate products are also good all-purpose surfactants.

Follow the label when mixing and applying herbicides and you will soon be the proud owner of a weed-free food plot.
Follow the label when mixing and applying herbicides and you will soon be the proud owner of a weed-free food plot.

Read the Label

Not sure what type of surfactant to use or even if you need one? The best way to figure that out is to read the herbicide’s label. Yes, the labels attached to herbicide jugs are as lengthy and complicated as a graduate-level chemistry textbook. The endless print within can be overwhelming enough to discourage even the most persistent readers. Don’t be one of them. Everything you need to know is in that wordy booklet.

You not only need to know if you should use a surfactant, but you also need to know how much herbicide to use. The label will tell you. It will even tell you which plants it will kill and which ones it won’t.

It will also tell you where you can and cannot use it. Although herbicides are generally safe, even unrestricted products can lead to some serious environmental damage when they aren’t used properly. Roundup, for instance, can be fatal to amphibians when it is used around ponds and other wet areas. Although, it isn’t the glyphosate that harms aquatic life. Instead, the surfactant added to the herbicide has been shown to kill a variety of organisms. Read the label and follow the warnings and recommendations, including safety gear recommended for you.

Go Generic

Herbicides may be a necessary part of the food plot and habitat management equation, but they can be costly. A 2.5-gallon jug of glyphosate-based Roundup Power Max, for instance, can set you back $70 or $80. Don’t fret. A number of generic glyphosate products are available for considerably less money.

That’s true for a number of other herbicides. The best way to find out if one product is comparable to another is to do an Internet search of a product’s label. Look for the active ingredient and then compare it to other herbicides.

Just make sure the percentage of the active ingredients are the same. Some glyphosate products have a lower percentage of glyphosate than others. That’s why they may be considerably less expensive.



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