From the Gamkeeper Podcast Studio – Episode 461 Old Field Management – Joined by the great minds of Bronson Strickland and Bonner Powell of Wildlife Investments. We talk about an often overlooked area on hunting properties, old fields. Subscribe on YouTube or Apple
Fire is one of the most powerful tools available for old field management, but according to wildlife biologists Bronson and Bonner Powell of Wildlife Investments, when you burn matters just as much as whether you burn at all. The same is true for discing. Get the timing wrong on either one, and a Gamekeeper can accidentally undo years of careful management in a single season.
Starting With Dormant Season Fire
For a newly established old field, Bonner recommends beginning with dormant season burns, generally falling in that February through March window before spring green up begins. This early phase of management is about getting the field started in the right direction, knocking back woody encroachment and encouraging the initial flush of native vegetation to establish itself. Bronson jokingly referred to this as the Genesis phase of old field management, the foundational starting point before more advanced techniques come into play.
Why Timing Has To Change After That Initial Phase
Once a field has been established and is functioning reasonably well, sticking exclusively to dormant season burns year after year stops being the best strategy. Bonner explained that varying burn timing becomes extremely important specifically for the sake of changing plant composition over time. Different plant species respond differently depending on what point in their growth cycle a fire passes through, which means a Gamekeeper who always burns in the same late winter window will tend to favor the same set of species indefinitely, potentially missing out on diversity that a different burn timing could unlock.
Shifting toward mid to late summer or early fall burns, generally falling in the growing season rather than the dormant season, allows a Gamekeeper to change the composition of a plant community without opening the door to problems that come with more disruptive management techniques like discing at the wrong time of year.
The Real Advantage Of Growing Season Fire
What makes growing season fire particularly valuable is that it changes plant composition without creating the same vulnerability to invasive species that comes with soil disturbance. Bonner was direct about this tradeoff. Both discing and herbicide application, when used at certain times or in certain ways, can open a field up to invasive species establishment, since bare or disturbed ground creates an opportunity for aggressive non-native seeds to take hold before desirable natives can reclaim the space.
Growing season fire sidesteps this risk almost entirely. Since fire does not disturb the soil the way tillage does, a Gamekeeper can use a late summer or early fall burn to shift which species dominate a field, favoring certain plants over others, without creating the kind of open ground that invites new invasive problems onto a property that has already had significant time and money invested into clearing out the last round of unwanted species.
Why Disc Timing Matters So Much
Discing follows a similar logic to burning, but the stakes for getting the timing wrong are arguably even higher. Bonner specifically warned against discing an old field in February or March, the same window that works well for dormant season burns. Discing at that time of year opens the soil up right before the primary spring germination window for many invasive and undesirable species, giving them a prime opportunity to establish themselves in freshly disturbed ground.
Instead, Bonner recommends confining disc work to the September, October, and November window. Discing during this fall period still provides the soil disturbance benefits a Gamekeeper might be looking for, encouraging certain native seeds in the seed bank to germinate, but it avoids handing that same advantage to the invasive species that would otherwise take full advantage of a late winter or early spring disturbance.
A Parallel Lesson From Wetland Management
Bronson connected this timing principle to a similar pattern he has observed in wetland moist soil management, which follows a comparable seasonal logic despite working with an entirely different type of disturbance. His general rule of thumb for wetland areas is to avoid touching them at all until after the Fourth of July, with August often standing out as the single most important month for wetland management decisions in his experience.
The core idea driving that recommendation, waiting longer before creating a disturbance generally produces better plant species results, mirrors exactly what Bonner described for old field burning and discing. In wetland settings, the specific disturbance is the timing of pulling water off a moist soil unit, but the underlying principle remains the same. Whether the tool is fire, discing, or water management, later season disturbance tends to favor higher quality plant species over the more opportunistic invasives that thrive when disturbance happens too early in the year.
Diversity Through Varied Disturbance
Bronson framed this entire timing conversation around a broader concept that comes up repeatedly in old field management discussions, the idea that diversity of disturbance ultimately drives diversity of plant composition. A field managed with the exact same tool, at the exact same time of year, every single year, will tend to plateau toward a fairly narrow set of species that happen to respond well to that specific disturbance pattern. Introducing variation, sometimes burning in the dormant season, sometimes burning during the growing season, occasionally discing in the correct fall window, keeps the plant community from settling into a static rut and instead continues pushing it toward a richer, more varied mix of species over time. This principle explains why experienced land managers rarely stick to a single rigid burn calendar year after year, and instead treat timing itself as an active variable to be adjusted based on what a field actually needs at any given point in its management history.
Why Getting This Wrong Is So Costly
The reason timing deserves this much attention comes down to the amount of work already invested by the time a Gamekeeper reaches this stage of old field management. A field that has already been treated with herbicide to remove sericea lespedeza, bermuda grass, or encroaching sweet gum and green ash represents real time and real money spent getting that field into a productive state. Discing that same field at the wrong time of year, or relying exclusively on dormant season fire indefinitely, risks handing back some of that hard won progress to the very invasive species a Gamekeeper worked so hard to remove in the first place.
Practical Considerations For Scheduling A Burn
Beyond the biological reasoning, there are practical realities that influence when a Gamekeeper can realistically execute a growing season burn versus a dormant season one. Growing season burns generally require more careful planning around weather conditions, humidity, and available personnel, since green, actively growing vegetation behaves differently in a fire than dormant, cured material does during the winter months. Gamekeepers new to growing season burning should consider starting with smaller test sections of a field rather than attempting a full property burn on the first attempt, allowing them to build confidence and experience with how fire behaves in green vegetation before scaling up to larger acreage. Consulting with a local prescribed fire council or an experienced contractor familiar with growing season burns in a specific region can also help a Gamekeeper avoid common mistakes during this transition from dormant season only burning toward a more varied, year round approach.
Building A Long Term Burn And Disturbance Calendar
Putting this all together, a realistic long term approach to old field disturbance timing looks something like this. In the earliest years of establishing a field, dormant season fire in the February to March window does the heavy lifting of knocking back woody competition and getting the field pointed in the right direction. Once that foundation is in place, a Gamekeeper should begin incorporating growing season fire, generally in the mid to late summer or early fall, to start shifting plant composition and building additional diversity without the invasive species risk that comes with soil disturbance.
Discing, when it is used at all, should be reserved for the September through November window rather than late winter or early spring, minimizing the opportunity for invasive species to exploit freshly disturbed ground. Over time, this combination of varied burn timing and carefully timed discing allows a Gamekeeper to continually refine and improve a field’s plant composition rather than simply maintaining a static baseline established in the very first year of management.
Conclusion
What ties all of this together is a broader truth about old field management that applies well beyond just fire and discing. The tool matters less than when that tool gets used. A herbicide applied at the wrong time of year underperforms. A burn conducted exclusively in the dormant season eventually plateaus in terms of the diversity it can produce. Discing at the wrong moment invites exactly the invasive problems a Gamekeeper spent years trying to eliminate.
For any Gamekeeper serious about getting the most out of old field management over the long run, learning to vary and correctly time these disturbance tools is just as important as learning which tools to use in the first place. A field that receives thoughtful, well timed disturbance year after year will continue improving in diversity and forage value long after a field managed on a single fixed schedule has plateaued, making the extra planning involved in varying burn and disc timing well worth the effort for anyone committed to the long game of old field management.
