Springtime is Spray Time

By Whitetail Institute Staff
Once hunting season is over, it can be easy to forget about our perennial food plots. If possible, try to avoid that temptation because controlling grass and weeds in perennial forage stands is important, simple, and pays off in a wide range of ways, especially for the next hunting season and for years to come. The Whitetail Institute’s Arrest and Slay herbicides are excellent tools in any weed-control arsenal, and they’re specifically designed with food plots in mind.


The answer is simple: we need to spray perennials for the same reason we change the oil in our cars — maintenance is easy, but necessary if we want our food plots to last as long as they were designed to last. And like car maintenance, there are two big reasons to keep grass and weeds in our food plots under control; because it maximizes performance, and it saves us money in the long run.

Nutritionally speaking, spring and summer are extremely important times in the lives of deer. That’s when bucks are growing antlers, and does are pregnant and, later, producing milk for their newborn fawns. Each of these processes takes huge amounts of nutrients, especially protein, and it takes high-performance forages to make sure they have all the protein they need. Whitetail Institute perennials are, in fact, high-performance forages. They’re designed to provide huge amounts of protein and remain highly palatable. If you want your perennials to remain as lush, nutritious and attractive as they’re designed to be,
though, you’ll have to do your part, and that includes controlling grass and weeds.
Also, just as keeping our cars maintained will save money in the long run, keeping weeds and grass in check can maximize the life of perennials. And that can really pay off. One of the main reasons for planting perennials in the first place is that they’re designed to last for multiple years from a single planting, which means you save the expense of having to replant every year. And be sure you understand — failing to control grass and weeds will shorten the life of your perennials just as not changing the oil in your car will shorten its life.

“The number one priority in maintaining perennial food plots is controlling grass. If you don’t control grass in a timely manner, it can take over the plot in a hurry.”
— Wiley C. Johnson, III, Ph.D.

Of all the information Dr. Johnson hammered into our brains, none was as often-repeated as this one. If you want your perennials to last as long as they should, you must control grass and weeds. Arrest and Slay are excellent tools for keeping grass and weeds in check. If you’ve wondered whether they are right for your particular planting situation, this article should give you the information you need.


“When maintaining perennial forage stands, herbicides should be considered as one tool within an overall weed-control plan. The overall plan should be integrated, meaning that it should include cultural, physical (or mechanical) and chemical weed control measures as appropriate to the forage being maintained and the weeds you want to control.”
— W. Carroll Johnson, III, Ph.D.

Whitetail Institute Weed and Herbicide Scientist As we get started, realize that no herbicide is going to be the answer to every weed and grass problem. Instead, as Dr. Johnson advises, herbicides should be considered one tool within an “integrated” plan to control weeds by attacking them from as many different angles as appropriate in the situation. “Cultural” weed control means keeping the forage itself in good shape
— healthy, and vigorously growing, making it harder for weeds to compete. “Physical (or mechanical” weed control means taking physical action against weeds, for instance by mowing them or pulling them up by hand. “Chemical” weed control, of course, means herbicides.
When it comes to formulating an integrated weed-control plan, each situation will be different. That’s why Dr. Johnson said “… as appropriate to the forage being maintained and the weeds you want to control.” In some cases, a weed-control plan may include all three measures — cultural, physical and chemical. In others, only two or even just one may be the optimum approach.
Below, we’ll explain how to determine whether a herbicide is appropriate for your intended use and, if so, how to mix the spray solution and apply it correctly. We’ll start with a few preliminaries you’ll need to know.


Herbicides are chemicals that “control” (kill) weeds or “suppress” them (keep them at bay enough to minimize their negative effects in crops), and they are described as either “nonselective” or “selective.” Non-selective herbicides kill or damage any plant they enter. An example is glyphosate, the active ingredient in many Roundup brand herbicides and generic equivalents. “Selective” herbicides kill or damage some plants (weeds) without harming others (crops). Examples include the herbicides offered by the Whitetail Institute, Arrest and Slay.


The herbicide label is the only source of information concerning the selection and use of the herbicide that is absolutely certain to be correct. It would be hard to over-stress how important it is that you consult the herbicide label in all matters relating to the use of any herbicide. If you don’t follow the label information and
instructions exactly, you may get no activity from the herbicide or even damage your forage plants — any number of results, and none of them are good. So again, read and follow all label instructions on any herbicide. The labels will tell you whether or not the herbicide is appropriate for your intended use, how to mix the spray solution, apply it, and dispose of any leftover solution — everything you need to know about the herbicide. To get the information you need from the label in order to correctly decide whether or not to use it, you need to understand how the labels are set up. As we go through that, it might be helpful if you pull up the Arrest and Slay labels on your computer so that you can refer to them as you read along. The Arrest and Slay labels are available online at www.whitetailinstitute.com/products/herbicides.html.


The herbicides appropriate for maintaining existing forage stands are “selective” in that they are designed to control weeds without harming forage plants. However, no readily available herbicide is appropriate for use in controlling all types of weeds in all types of forage stands. Instead, as we’ll explain in more detail below, you have to first make sure that the selective herbicide you choose will (1) control the specific weeds you are facing, and (2) do so without harming the specific forage plants you’re maintaining.

That’s because herbicides work by interfering with one or more critical parts of the weed’s life and/or reproductive process, and weeds survive and reproduce in many different ways. Also, different weed types may appear very similar but have very different life and reproductive processes. To make matters even more difficult, some weeds and forage plants live and reproduce in ways so similar that no readily available herbicide will control the weeds without harming the forage plants.
If you’re confused by herbicides, don’t feel bad. You’re certainly not alone. You’d have to be a weed-and-herbicide scientist to understand all the technical details of exactly how each herbicide works. The good news is that you don’t have to understand all the technical details because that work has been done for you, and all you need to know is the comparatively simple, step-by-step process that has been set up for you to take advantage of it.
Arrest and Slay are selective herbicides offered by the Whitetail Institute and specifically designed for controlling grass and weeds in food plots. Arrest is designed to control most kinds of grass, and it is labeled for use in any Whitetail Institute perennial forage stand, any other straight clover or alfalfa. Slay is designed to control many kinds of broadleaf weeds and a few heavier grass types, and it can be used in established stands of Imperial Whitetail Clover, and any other straight clover or alfalfa. Both are within the family of herbicides referred to in the industry as “small-weed” herbicides, which are designed to provide optimum control of labeled grasses and weeds that are still in “seedling” stage (young — before roots have matured).


Remember what we said earlier? Selective herbicides work by interfering with a grass or weed’s life or reproductive processes, and although two types of grass or other weeds may look very similar, their life and reproductive processes may be quite different. That’s why herbicide labels are specific as to grass and weed type — the information the label gives for different types of grass and weeds is not the same.

Step 1. When deciding whether Arrest and/or Slay is right for your situation, your first step is to specifically identify the grass or other weed you’re facing. For example, identifying an unwanted plant as “grass” isn’t
enough; you have to identify it more specifically as “Johnsongrass” or “Orchardgrass” or “Crabgrass”, etc. If you’re not sure exactly what a grass or other weed is, you can usually get it identified easily and quickly by your County Agent. Alternatively, you can e-mail detailed, close-up digital photos of the top of the weed, its stem and foliage, and its roots to the Whitetail Institute. When preparing photos, make sure you take them against a white background such as an old pillowcase or bed sheet, and again, make sure the photos are clear and detailed.

Step 2. Specifically identify the forage plants you want to maintain in your food plot. If you’ll be maintaining a Whitetail Institute forage, this step is quick and easy. As we said earlier, Arrest is safe to spray (as directed by the label) in any Whitetail Institute perennial forage stand. Slay is safe to spray in stands of Imperial Whitetail Clover that are “established” (meaning that newly planted clovers must have grown to a height of three inches and have all their leaves unfolded before you can safely spray them with the Slay solution). For other forages, specifically identify the forage plants just as you did the grass or weeds in Step 1, and consult the herbicide labels.


If you’re to this stage, then you’ve already gone through Step 1 and found that the label on the herbicide you’re going to use says that the herbicide (1) will control or suppress the grass or weeds you’re facing, and (2) do so without harming your forage plants when used according to the label’s instructions.


On the herbicide label, look next to the name of the grass or weed you’re trying to control. There, you’ll find a chart telling you exactly how much water and herbicide to use for each specific grass or weed type, and whether that rate needs to change if the grass or weed is older than seedling stage. On the Slay label, you’ll also see that adding a surfactant or agricultural oil into the spray tank at the time you mix the Slay
solution is required for Slay to work. The Whitetail Institute recommends Surefire Seed Oil for this purpose.
A great way to make sure you get the correct amounts of each component into the spray tank is to start by adding all the water specified except a gallon, then adding the specified amounts of herbicide and any adjuvants such as Surefire Seed Oil and/or ammonium sulfate, and then adding the last gallon of water.


Again, the herbicide label will also tell you whether or not a surfactant or agricultural oil should be put into the tank with the herbicide and water when the spray solution is mixed, and the Slay label says a surfactant or agricultural oil is required for Slay to work. Although the Arrest label says that surfactants and oils are not required for Arrest to work, the Whitetail Institute strongly recommends adding an oil to the Arrest spray tank when dealing with perennial grasses, or grasses that have mature roots. In such cases, adding an oil to the Arrest spray solution can have a noticeable effect in increasing the action of the herbicide. The Whitetail Institute specifically designed Surefire Seed Oil for use with Arrest and Slay. Oils tend to make the herbicide solution much more active than surfactants do and also help the herbicide penetrate the plant’s leaf, and they can be either vegetable-seed-based or petroleum-based. Surefire Seed Oil is a vegetable-seed-based oil, and it also contains an anti-foaming agent to help the user properly mix the herbicide spray


The Slay label says that high nitrogen liquid fertilizers such as ammonium sulfate “may be applied” as part of the Slay spray solution. In other words, it’s okay to include them in the Slay spray tank, but not mandatory. The purpose for which such fertilizers are added to herbicide spray solutions is to combat the negative effects of hard water on a herbicide’s efficacy — to help buffer this effect and allow the solution to stay longer in a form that will provide optimum control. If you decide to add ammonium sulfate to the Slay spray tank, make sure it is “spray grade” so that it will flow through your sprayer nozzles without clogging them.


“The main issue in deciding when to spray Arrest is how old the grass is — you need to spray it as soon as grass appears and starts to actively grow.”
— Dr. Wiley C. Johnson, III, Ph.D.
Dr. Johnson had a knack for breaking down instructions simply so that we could get the key information stuck in our brains. It may help, though, to explain a few of the key points behind his instruction.


Generally, most herbicides enter grass and weeds in two ways: “foliar uptake” (through the weed’s leaves), “root uptake” (into the weed’s roots), or both. Arrest is a foliar-uptake herbicide. Slay is a foliar-uptake and root-uptake herbicide. 

For a foliar-uptake herbicide like Arrest to enter a plant, the plant must be actively growing. Here’s a simple explanation of when grass is “actively growing” that anyone who regularly mows a lawn will readily understand. Think about early spring when you see your lawn taking on a slight green tint. At that point, your lawn is waking up, but it is not yet “actively growing” for our purposes. Next, think about a few weeks later when you see the grass getting taller and wonder if your lawn mower is going to start. Now, the grass is “actively growing” — the grass is getting taller, and doing so quickly. Other factors that may affect active growth are seasons, excessive heat, drought, and mowing.
The same is true of the foliar-uptake aspect of Slay. It allows Slay to control weeds that are actively growing, and its root-uptake aspect allows it to keep controlling new weeds that sprout from dormant seeds after you spray.


Arrest can be sprayed on any Imperial perennial no matter how young it is. With Slay, though, you need to wait for newly planted plots to get going before you spray. Specifically, the Slay label says that newly planted clover or alfalfa should not be sprayed until at least the “second trifoliate stage” (until after the new clovers grow to at least three inches and have all their three leaves unfolded).


Like most herbicides, Arrest and Slay control young weeds better than mature weeds. For optimum control, try to spray Arrest and/or Slay while actively growing grasses and weeds are still young — as a rough ballpark, before they grow to a height or length of about 6-12 inches.


All herbicide labels provide solid advice about the importance of wearing protective clothing when handling and applying herbicides. The most basic important items include chemical-resistant gloves, eye protection,
long-sleeve shirt, long pants, and boots. Even though Arrest and Slay are among some of the least toxic herbicides, be sure to follow the label’s advice about protective gear — they’re on the label for a reason.
Often, the food plots we spray aren’t near a potable water source, so remember to bring along what you need anytime you’ll be spraying your food plots. Whenever Dr. Carroll Johnson applies herbicides, he carries a “possibles bag” that includes several gallons of potable water for clean-up, and emergency bathing in the event of a spill or exposure due to a ruptured spray line, as well as soap, household ammonia, an eye-flushing kit, and extra personal protective clothing. Dr. Johnson considers ammonia “indispensable when using a sprayer of any type.” Mix one quart of ammonia per 25 gallons of water and flush the sprayer with the mixture to clean the sprayer, ensure optimum sprayer performance, and minimize the risk of herbicide contamination that might injure desirable plants on a subsequent spray trip.


Hopefully, this article has helped clear up any confusion you may have had about herbicide use in maintaining existing forage stands. Again, the herbicide label is the only official source of information about Arrest, Slay or any other herbicide. The Arrest and Slay labels and an FAQ are available on the Whitetail Institute’s website at www.whitetailinstitute.com/products/herbicides.html. And remember, if you still have questions after reading the Arrest or Slay label, call the Whitetail Institute for advice before you spray.