30 Years of Deer Habitat Management, Part 2: Into Fields and Forests

January 8, 2024 By: Craig Harper

Deer hunters today are more knowledgeable about deer habitat management than ever before. We are driven by a desire to produce better deer and better hunting, and science gives us better information and improved strategies. The times really started changing 30 years ago, and as I wrote in Part 1 of this series, it all began with food plots. Then, science led us into fields and forests. Let’s pick up the story there.

We Moved into Fields

It was in the late 1990s and early 2000s that we began to look at “weeds” much differently than we used to. While collecting forage selectivity data in University of Tennessee cafeteria plots, my students and I noticed how deer selectively ate various weeds in the plots. 

I remember collecting leaves of some of these weeds in 1998 and sending them to the forage lab for nutritional analysis, almost as a joke to see what the forage specialist would say. Upon conducting the analysis, he responded via e-mail: “What are these forages? They are outstanding quality.” 

I still have his e-mail and the analysis of pokeweed and common ragweed

I and many others had been researching native grasses since the 1990s. By 1999, methods had been ironed out to easily establish native grasses in one growing season, and people began planting native grasses like crazy to establish bedding cover for deer and improve habitat for quail and rabbits. However, by the mid-2000s, we had figured out that native grasses were not a limiting factor for anything. Instead, it was the forbs. But the planted native grasses were out-competing the forbs in the planting mixtures. 

John Gruchy helped determine best management strategies for old-fields and other early successional plant communities. Here, John is in a field that just the year prior was thick, planted, native grass but now has a good complement of forbs following herbicide and disking treatment.

Forbs are king with regard to nutrition for deer, seed and invertebrate availability for birds, cover for turkey and quail broods, and even cover for fawns. We began to look at fields dominated by forbs essentially as warm-season food plots. The nutritional value of forbs exceeds maximum amounts needed for lactating does and bucks growing antlers. 

We learned that on the vast majority of sites, you do not need to plant anything, especially not native grasses, but simply work with the existing seedbank to stimulate desirable forbs.

Over time and through research conducted by John Gruchy, Wade GeFellers, and Bonner Powell, we documented forb response to timing of disturbance like mowing and disking, timing of fire, and pre- and post-emergence applications of various herbicides. We learned that on the vast majority of sites, you do not need to plant anything, especially not native grasses, but simply work with the existing seedbank to stimulate desirable forbs. Instead of planting what you want, simply kill what you don’t want and let Mother Nature fill the void! This became my mantra.

We documented how spot-spray applications once per year in spring/summer reduced unwanted species and increased plant species richness. This work changed how we manage fields for deer. Today, we can quickly transform a field dominated by non-native grass – which provides literally nothing for deer – into a plant community that provides 1,000 to 3,000 pounds of high-quality forage per acre and at the same time provide outstanding bedding cover and create exciting hunting opportunities. These approaches now are being used all over the eastern United States. It has been fascinating and most rewarding to watch people who once thought artificial pelletized supplemental feed was necessary to provide nutrition for deer discover the nutrient content and deer selectivity of “weeds” and how much tonnage these plants can provide!

Bonner Powell documented advantages of using the seedbank and burning when managing early successional communities, but he also helped evaluate strategies for perennial food plots. Here, Bonner is presenting results at the Southeast Deer Study Group meeting.

Timber Forest Stand Improvement

After taking several forestry and silviculture classes in the late 1980s, I learned much could be done in hardwood stands to improve deer habitat. Of course, regeneration methods provide a flush of browse and improved bedding cover for several years after timber harvest, but regeneration is not an option for many stands. Young hardwood stands are not ready to regenerate, many mature stands do not contain seedlings of desirable tree species, especially oaks, to replace harvested trees, and many stands do not contain trees that will pay their way out of the woods. 

Such was the case on my family’s property in the Piedmont of North Carolina in the 1980s. However, I still wanted to do something to improve conditions for deer in the woods. After taking Dendrology, I knew the tree species, and I knew which species provided something for deer and which ones did not. Timber Stand Improvement was an option to influence species composition, but many of the trees that provided lumber value (either at present or in the future) were not species that provided food for deer. So, what I wanted to do really did not fit a “timber stand improvement” objective. 

That’s when I decided to call it “Forest Stand Improvement,” which allowed me to fit any objective, and I simply started killing or felling every tree in the woods that did not provide something for deer at some time of the year. After much experimenting with girdling and herbicides, I soon had a method that would kill any tree I treated

I visited Bobby Watkins, who worked with BASF, in Mississippi in the late 1990s, and he showed me areas where he and Steve Demarais at Mississippi State University were thinning pines, applying imazapyr to reduce hardwood encroachment (mostly sweetgum), and using fire to stimulate forbs and grasses. Their work transformed pine management for deer and turkeys, and I wanted to do the same in hardwoods. Bobby, Steve, and later Bronson Strickland and others, highlighted their work over the years in NDA publications. Their approach spread throughout the Southeast, especially in loblolly pine stands. 

Transitioning forest to early succession by using various herbicide applications and fire can dramatically increase the nutritional carrying capacity for deer. Jordan Nanney measured the effects of these practices at a number of sites on the Cumberland Plateau from 2013 to 2015.

Hinge Cutting

Around 2010, a practice known as hinge-cutting started getting lots of attention, particularly in Michigan and other portions of the upper Midwest where property sizes are small and land managers were doing everything they could to help attract and hold deer on their property. Hinge-cutting involves making a partial cut through the stem of the tree and leaning the tree over, often aided with a long push-pole. The practice can be dangerous, especially if hinging trees greater than 8 to 10 inches in diameter and when hinging trees at a height above your shoulders. 

Early on, people cut trees of all types and sizes, in any haphazard direction, with and without a push-pole or assistance. Foresters began to howl that this new practice to create deer bedding cover was destroying forests by killing and limiting regeneration of desirable species, and cluttering stands with massive amounts of debris that would make entry into the stand very difficult if remaining trees were harvested or if steps were taken to improve species composition. 

However, when conducted appropriately, just the opposite occurs. We can hinge undesirable species as well as desirable species that are suppressed or with poor form, leave desirable stems standing, and improve cover that deer gravitate to overnight. Over time, we learned that the “hingeability” of a tree varies by species, and that hinging can be combined with killing trees via girdle-and-spray or hack-and-squirt and also with felling. 

We learned that a stand does not have to be “shut-down” as if a tornado ravaged the area. If we simply lessen visibility to less than 10 to 15 yards by hinging trees about 4.5 feet above ground, and maintain trails, tunnels, or avenues for deer to move, they are attracted to these sites like bass to a brushpile.

In Part 3 of this series, we take fire into hardwood stands. Then we end with a look ahead at the future of deer habitat management. Keep an eye on NDA’s Thursday newsletter to read the conclusion.

About Craig Harper:

Dr. Craig Harper is a Professor of Wildlife Management and the Extension Wildlife Specialist at the University of Tennessee. Craig is a regular contributor to the NDA website and a Life Member of the NDA. Dr. Harper and his graduate students concentrate their work on applied management issues, including forest management, early succession management, food plot applications, and the effects of quality deer management.