Native Browse Is the Diet. A Food Plot Is the Supplement.

STEP 1 · Protein needs

Age, sex, and the month shape protein requirements

Missouri Extension's nutrition guide, written by Pierce, Vandeloecht, and Flinn and reviewed in November 2022, describes white-tailed deer as browsers. Their foods include woody browse, forbs, hard and soft mast, and some grass. Studies of deer food habits have found more than 600 plant species in Missouri deer diets. Deer often choose growing tips, where plant tissue is most tender, juicy, and rich in nutrients. No single food leads their diet all year. What they select depends on how appealing it is to eat, what is available, and the season.

A deer's age and activity alter its protein requirement. Missouri presents those needs in a table.

Nursing places the greatest protein demand on does, and raising twins increases that need. Milk from deer contains an average of 8.2 percent protein. Antlers, once hardened, contain about 45 percent protein. Yet growing and maintaining the body take priority, so inadequate protein through the spring and summer leads to smaller antlers. Missouri describes dietary protein of 16 percent as generally optimal for growing antlers.

The guide's example involving penned deer comes from real research, though it is easy to extend the lesson too far. Two-year-old bucks eating a diet with 8 percent protein grew half as much antler mass as those eating 16 percent protein. By age 4, the guide reports a 20-inch gap in antler size but does not identify which antler measurement those inches describe. It calls the research studies of pen-raised deer. Captive deer eating a formulated diet face different conditions from a wild herd finding food in a woodlot. Still, the gap shows that access to green plants alone does not amount to a nutrition plan.

The prescribed burning review from the University of Georgia, by Hopper, D'Angelo, and Kohl, published in 2021, instead provides a single range for optimal growth: 13 to 16 percent protein. It cites research from 1956. Its synthesis differs from Missouri's table organized by activity. Treat both as ranges rather than averaging their values.

Energy accounts for the other half of the picture. During fall, deer look for carbohydrates to turn into stored fat, helping explain the appeal of grain and acorns. According to Missouri, males engaged in breeding can shed up to 30 percent of body weight. Of the energy does spend producing fawns, about 20 percent goes toward pregnancy and about 80 percent toward nursing. Milk output peaks 10 to 37 days following birth. In Missouri, the usual periods of greatest stress are winter and late summer: food is scarce while lactation, growing antlers, or recovery from the rut remains underway.

STEP 2 · Native plants

Common native plants fall on either side of those requirements

The P3618 field guide from Mississippi State Extension gives common plants a crude protein range and a preference rating. Hamrick, Strickland, and Demarais explain that they cover commonly selected forage in Mississippi and the Southeast, rather than every species deer consume. Strawberry bush was omitted because deer favor it so strongly that the plant is rare. For each plant, the publication provides an average, a range, and a preference class drawn from published studies. It does not identify the season behind each value.

Comparing the averages with Missouri's requirements produces two groups. Pokeweed, partridge pea, ticktrefoil, and ragweed have averages of 17.5 to 25.9 percent. Those values fall within or above the lactation requirement of 14 to 22 percent and exceed the antler figure of 16 percent. Old-field aster, wild lettuce, blackberry, and greenbrier have averages of 11.3 to 13.2 percent. They exceed the range for adult maintenance and the yearling requirement of 11 percent, while remaining below the lactation minimum, 14. We made this comparison using the two publications; neither source makes it. It suggests a difference between woodland offering only acorns and woody browse and woodland that also supplies forbs deer can reach.

Missouri's early successional guide lists the same four high-protein forbs, plus asters, among plants encouraged by disturbance at ground level. Mississippi State says ragweed and partridge pea seeds remain in the soil and often sprout following prescribed fire or soil disturbance. It also reports good ticktrefoil growth following prescribed fire. Blackberry commonly occurs in early successional growth following timber harvest. Our early successional guide explains forage production in pounds and the cutting and burning that produce it.

STEP 3 · Seasonal swing

Winter can bring a drop in a plant's protein concentration

Figure 5 in Missouri's nutrition guide published as a PDF uses shading to mark when each food is available by season, alongside its printed protein range.

The chart puts greenbrier as high as 35 percent protein through the spring and summer, far above the lactation range. For fall and winter, its range drops to 5 to 12 percent, roughly around the requirements for adult maintenance. Sumac shows a similar seasonal pattern. Missouri explains that many native plants and browse species rich in protein mature through the spring and summer, then lose palatability through the fall and winter. As summer progresses, protein tends to decline while lignin increases. For fall and winter, the text lists clovers, lespedezas, coralberry, greenbrier, sumac, and soft mast, with acorns identified as a primary food. Corn and acorns provide little protein but substantial energy, making them staple foods wherever they grow.

P3618 assigns no season to its values. Read the averages as rough figures drawn from published studies without seasonal labels. They allow a loose comparison among plants, rather than an exact protein value for a particular time. Turn to Missouri's chart for seasonal timing.

STEP 4 · Food plots

Plots provide a supplement during stressful months

Mississippi State describes cool-season and warm-season plots as a boost to nutrition within the larger diet picture. They provide supplemental food during stressful winter and summer periods. It says actively managing native vegetation matters at least as much and may deliver more benefit per dollar than producing food plots. It also says forbs and leafy browse account for most of the diet. Missouri says cool-season plots combining oats and winter wheat with clovers and other legumes provide protein during winter, when protein foods are generally unavailable. It describes food plots as supplements to natural food sources rather than substitutes for them.

Figure 5 also lists protein levels for food plot crops. Forage soybeans are shown at 25 to 35 percent protein during summer and fall. The spring and winter figures are 15 to 30 percent for red clover and 17 to 27 percent for ladino clover. During fall and winter, turnip tops are listed at 17 to 24 percent and turnip roots at 12 to 15 percent. Corn is listed at 5 to 8 percent.

A Tennessee burning experiment discussed in our guide to early succession compared warm-season plots with woodland that had been thinned and burned. According to the summary of the forest forage study, plots supplied more available forage than all woodland treatments other than a retention cut combined with fire. The authors suggest using plots to cushion browsing pressure during herd reduction, rather than sustaining an artificially large herd. The brief also advises that managing both the forest and its deer population may make food plots unnecessary for appropriate forage availability.

STEP 5 · Grasses and invasives

A food appearing on the menu does not establish preference

According to Purdue, most grasses offer deer little nutrition and are seldom eaten, except for cereal grains such as wheat. Missouri reports that deer eat very little grass of any type in summer. Native warm-season grasses have value as cover for fawning and winter and as fuel for fires. Missouri considers mowing the least desirable method for maintaining early successional vegetation because repeated, frequent mowing deposits thatch over the seed bank, while mowing during the growing season destroys fawning cover. Its nutrition guide recommends leaving pastures unmowed during the peak fawning period, May 15 to July 1.

Invasive shrubs make the food picture harder to sort out. Purdue Extension says bush honeysuckle, multiflora rose, and Japanese stiltgrass offer poor-quality forage. According to that guidance, when deer eat these plants, there are more deer than the habitat can feed, too little food, or both. Mississippi State includes Japanese honeysuckle, a separate plant, because deer eat it and gives its average protein content as 10.6 percent. It also describes the plant as a nonnative invasive that often overtakes and replaces native vegetation. Those findings can both be true. We read them to mean that a honeysuckle thicket replacing ragweed, blackberry, and greenbrier may reduce summer protein, because its 10.6 percent average falls below the figures for lactation and antler growth. Honeysuckle is semi-evergreen, staying green into winter after ragweed and blackberry have stopped doing so. The sources did not measure the overall effect across a full year.

Inclusion in a plant list also does not establish preference. Purdue includes poison ivy as a species deer select. Mississippi State, however, gives it a low to moderate preference rating.

STEP 6 · Reachable forage

A protein-rich stem counts only when deer can reach it

Purdue says a young forest loses forbs and brambles to shade once its canopy closes, while woody browse grows above the height deer can reach. How quickly deer eat the remaining accessible browse then depends on deer density. Missouri says vegetation gradually declines in both quantity and nutritional quality when deer numbers exceed the habitat's capacity to support them. The herd develops poor body condition, fewer young join the population, and bucks have small antlers. The Georgia review also says browsing could stop plants from becoming established again after a burn in places with abundant deer. If deer chew a stem with 19 percent protein down to a nub in June, that stem offers no forage in July. This is our interpretation of the sources, rather than a measured result.

STEP 7 · Field method

Learn ten plants, then check for bites

Mississippi State concludes that knowing these plants offers a starting point for tracking deer use and relative browsing pressure. Those signs indicate the condition of habitat and the status of the population. Purdue similarly suggests searching for the species it lists to assess forage quality in open ground and woodland.

Start with ten plants: blackberry, greenbrier, sumac, goldenrod, asters, wild lettuce, pokeweed, partridge pea, ticktrefoil, and ragweed. Visit the property once per season. For each species, record its presence, whether it is within a deer's reach, and the amount of use it shows. Ragweed left untouched in July has received less browsing than stems showing heavy use. These observations can flag possible shortages of seasonal forage, though they provide no protein measurement.

Use our rule to interpret those gaps. The sources support its individual parts, but none tested this sequence. When the plants are absent, first try sunlight or disturbance of the ground. When plants remain but have been bitten down to nubs, examine browsing pressure. Heavy use by itself establishes neither herd size nor the reason forage was depleted. If forage is plentiful in summer but nothing green remains late in winter, that shortage makes the case for supplemental food. Our food plot design guide addresses where to place plots and how to size them for an actual parcel.

Here is our opinion, separate from the cited findings: if a plot supplies all the green deer food we can locate on a property in July, that herd is leaning on supplemental food. We would devote the next day of chainsaw work to bringing in sunlight before buying another kind of seed. That judgment comes from the gap between the requirements in Missouri's table and the closed-canopy forage values discussed in our guide to early succession. No experiment measured antlers on your ridge.