Why You Should Research Seed Size Before Planting Mixes

In 1974, after spending a year building a wildlife program here at Stephen F. Austin State University, my colleagues and I decided to create an Institute devoted solely to deer research and management—The Institute for White-tailed Deer Management & Research.

At that time, I had accumulated a host of peer-reviewed publications in journals, but this success left me with less than satisfaction. Much of the information remained hidden from the folks who actually needed it, so our goal would be to conduct meaningful research and get the results into the hands of people who really need it, landowners and hunters. We decided on conducting what today is called “focus groups,” to find out exactly what people needed to know.

Our focus groups were made up of landowners, hunters, foresters, and wildlife managers. We started out by asking a simple question: “What do you need to know?” Invariably, the first answer was, “Can we plant something for deer?” The second answer revolved around why good bucks were so hard to kill! We developed our first 20-year plan from these meetings; and today, we are putting together our third such plan.

The goal of our first plan was to study plantings for whitetails and conducting behavior studies on bucks. I grew up in Central Texas, where it was common to plant “oat patches” for hunting. Little thought was given to the benefits to deer; instead, the goal was just getting them to the gun. An “oat patch” was simply feed oats scattered on the ground and disked in with maybe a 50 lb. bag of fertilizer to the acre.

The oat patches did fairly well at attracting deer, but if there was a hard freeze, you could forget about the value of these plantings. Feed oats freeze out at 28 degrees, since they are mostly Scandinavian-derived plants developed for the warm season. Obviously, our research would have to focus on more useful species and varieties.

After a little thought, I remembered that Nacogdoches County, Texas, at that time was the home to several dairies. I asked myself: Who would know more about growing forages for ruminants than a dairyman?

Universally, when asked what they grow, the dairyman responded, “A full seeding rate of cereal and grain and a full seeding rate of clover.” That information became the backbone of our deer forage research! Today, we are the longest running deer forage research facility in the U.S. Since then, we have tested and researched virtually every plant suggested for deer food plots, not just here in eastern Texas, but throughout the range of the whitetail.

We focused initially on cereal grains, including oats, wheat, rye, triticale (wheat x rye) and even barley. Since there was a developing interest in Gulf Coast ryegrass, we later included it in our tests. The first goal was cold hardiness, followed by deer preference and nutritional composition.

Initially, oats failed the first test (cold tolerance), until John Butler of Arkansas talked us into trying a new variety out of the LSU cereal grain program that had significant cold tolerance. This work led to the Buck Forage brand of oats, which to this day remains the most cold hardy. However, we also found that wheat and rye also were cold hardy, but of the three, rye was the least preferred cereal grain. Ryegrass failed at nutritional composition and preference unless deer had no other choice! It also has become an invasive plant that is very difficult to get rid of!

Cool season cereal grains offer the advantage of high early growth in the fall, which has high digestible energy, the most important deer nutritional element. However, they begin to mature with the onset of spring temperatures, losing digestibility in the process. Deer use falls off in most areas by May.

That fact guided us to our new line of research: legumes. The dairymen had suggested we include a clover in our deer plantings, varieties also planted mostly in the fall in the South and spring in the North. The cooler weather conditions up north lend to lush spring and summer growth.

The first clover varieties we studied were crimson and arrowleaf, popular in the South. The problem with crimson was that it was developed for over-planting in Bermudagrass pastures, that became dormant at the first frost. Planting crimson increased green forage through much of the winter, but this variety was bred to flower early in spring before the grass broke dormancy. Arrowleaf clover was popular as a stand-alone forage that not only could be planted in the fall, but had high heat tolerance, lasting sometimes until the end of summer, making it a “semi-perennial” plant.

In the North, very few managers at that time were planting for deer; believing that the ubiquitous alfalfa and soybean fields provided enough for the deer. Cereal grains were seldom planted for deer, and clovers did not appear until much later. The two most common clovers we examined in the North were red and white; the first being annual and the latter being somewhat perennial. White clover became the most popular in temperate climates, but had significant soil/site needs, while red clover was more adapted to varying conditions.

At first, we looked at food plots that were divided into cool and warm season portions, at that time not mixing varieties. By the late 1980s, we had expanded our research to fit the dairymen’s recommendation to evaluation of cereal grain-legume mixed plantings.

The Evolution of See Mixes For Food Plots

My graduate student, Dr. Billy Higginbotham, was given the job of evaluating all the potential deer forages for cool and warm seasons, as part of his doctoral dissertation research. Dr. Higginbotham discovered that deer preferred cereal grains most in the fall and winter, then shifted use over to clovers as spring emerged. The logical conclusion was that either a mixed planting of the two or side by side plots would greatly expand the nutritional supplementation for deer.

We tried both, discovering that the split plots were the easiest to develop, because the cereal grains tended to put on growth earlier than clovers, often crowding out the latter. The next focus shifted to what seeding rates were best to ameliorate this problem. Most cereal grains are planted at broadcast rates of 80-120 lbs./acre (half that drilled), so portions of these rates would have to be evaluated. Our findings were that a reduced cereal grain planting rate of 50 percent would be the maximum rate for mixed plantings with clover.

In those days, very few landowners and managers used high-end equipment like seed drills for planting deer food plots. Most simply broadcasted seed and soil amendments and disked the site to cover the seed. In order to plant a mix, you would need to broadcast the large seed such as cereal grain, disk in the seed to the recommended depth, then come back and top seed with clover, and use a device called a cultipacker to get the seed to the proper planting depth.

No-till drills such as the Great Plains, John Deere and Land Pride (and many others) can include a small seed attachment that allows the operator to plant two different sized seeds at the same time; and, at a lower seeding rate. Unfortunately, such equipment costs north of $15,000, although there are some new, smaller machines on the market that are more affordable.

By the turn-of-the-century, the food plot business had blossomed to dozens of companies, each selling a host of species and varieties, mostly as mixes. At first, mixes included many seed types, often large seeds mixed with very small seeds. This created a problem in that, 1. It was not possible to plant each seed type at the proper depth, and 2. Physical activity caused the seed to stratify in the bag or planter bin!

This caused the seed to be distributed disproportionately across the food plot, producing “spotty” distribution of plants. Later, companies began offering mixes of seeds of approximately the same size and have largely reduced the significance of this problem.

Properly Planting Seed Mixes For Deer

There actually are three types of planting: till, low-till, and no-till. Till planting involves site preparation to produce a totally clean planting bed, through use of herbicides and/ or mowing and disking. Once the site is prepared and soil amendments incorporated, the site either is planted by broadcast and re-disking or drilling.

Low-till planting usually involves mowing the site (and perhaps herbiciding), then drilling in the seed with one of the low-till drills through the dead plant material. Lastly, no-till planting may involve spraying the site with an herbicide that kills all vegetation, then broadcasting the seed over the top. Simple mowing may also be used for this method. You must be careful not to produce too much organic matter on the ground surface, since this will prevent the seed from germinating properly.

The cost of these activities increases from no-till to till; however, the yields often are higher. Furthermore, if you are planting a perennial, the lifetime of the crop will be longer after tilling than from no-till.

What do we do? If you pay attention to social media, “food plotting” almost has become a religion. There are several blogs devoted solely to food plots. To read some of these, you would come to the conclusion that if you do not do it the way they recommend, you are a heretic! But in reality, there are more ways than one to food plot effectively.

Each year, we receive hundreds of questions from landowners and managers about how to eliminate weeds from food plots. Yet, a food plot plant is nothing more than a cultivated weed! Many weed species invading food plots are quite nutritious for deer. Remember, a food plot does not have to be pretty to benefit your deer. Rather, one that has a reasonable standing crop of food, even mixed with “good weeds,” will satisfy your management needs.

We view the value of seed mixes is to give the basis for determining what will do well in each of your plots. Food plots are very site specific, and two plots, only a quarter mile apart, may support very different species and varieties. Keeping records on each food plot—including soil analyses, amendment amounts added, and data on what was planted and what did well—will greatly increase success.

If we are evaluating a mixed seed product, we prepare a thorough seed bed and spread the seed at their recommended rate. Subsequently, we spend a lot of time on our hands and knees, examining the plants that grew from that seed. It takes some investigation about what each plant looks like, but this is well worth your time. I promise you only a few of the plants will do well in that plot. Once you identify the winners, it might be better to purchase pure seed in the future and plant them at the exact recommended rate.

Let me give you a real-life example. Years ago, a company came to the Institute wanting us to evaluate their seed mix. We asked for the individual seeds to be separated for better analysis and testing, but they could not do that! We planted the mix in several replicated plots, then evaluated production and use of each species/variety in each replicate.

There was one plant in particular that was not only thriving, but the deer were “hammering” it! At that time, this plant was not even recognized by companies selling seed. It just happened to be in a seed mix purchased by the retailer from abroad. That plant turned out to be chicory. It started a research program that goes on to this day, and chicory remains one of the few “new” plants that we have added to our short list of successful plants for deer.

Beware of Weeds in Your Food Plots

I will give one last bit of advice. Be very careful to examine the seed labels required by law on any seed mix you purchase. Look for the tested amount of “weed” seed in the bag. It may look like a very small, inconsequential amount, yet a single noxious weed seed can grow quickly into a real problem.

Toxic mustard is my visual aid for this warning. It arrived here at the Institute in a mix from one of our seed sources in 1975, and we are still killing it today! There is no way to give you a complete primer on food plot mixes in this short space, but I hope I have given you some things to consider. Good planting!

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