There is no set standard, but it should be wide enough for the fuels along the boundary of the burn unit. Typically a bareground line 4 to 10 feet wide is sufficient, but narrow cow trails and even mowed lines can be safely used. The width of the firebreak can be offset by reducing the amount of fuel right next to the edge of the burn unit by mowing or shredding to diminish flame heights and fire intensity.
Managing Firebreaks for Wildlife
Managing native vegetation with prescribed fire should be an integral part of any land management plan. Maintaining adequate firebreaks is necessary to implement a prescribed fire program. Firebreaks serve several functions, including defining the burn unit perimeter and providing access to burn units. However, they can also be used in other ways to benefit wildlife and improve hunting. Food plots are often used to attract wildlife and make various game species more visible and increase hunting success. In some cases, food plots can also provide beneficial forage for species such as wild turkey (Meleagris gallopavo) and white-tailed deer (Odocoileus virginianus).
Managing Herbaceous Cover
Firebreaks may be the only accessible and open areas for food plots. Firebreaks can be disked seasonally, annually, or every few years; thus, they can be used for annual or perennial, warm- or cool-season food plots. Perennial plantings are best suited for firebreaks around areas that are burned on a fire-return interval of >3 years. If the firebreak is planted in the season prior to burning, a “green” firebreak may provide suitable protection, depending on plant moisture, dead plant material, etc. Otherwise, firebreaks should be disked (optimally) or at least mowed just prior to burning. Thus, it is may be necessary to re-plant the firebreak after burning.
Firebreaks do not have to be planted. They can be left fallow to allow native forbs to germinate. Often, native species such as sunflowers (Helianthus spp.), crotons (Croton spp.), and ragweeds (Ambrosia spp.) germinate in fallow firebreaks depending on the time of year they were disked. Fallow food plots, both in fields and in woods, can be very attractive to wildlife. When firebreaks occur in woods, it is not uncommon for woody species to sprout and grow in the firebreak. That’s OK. Browse and cover from low-growing woody plants are important sources of food and cover for several species, especially white-tailed deer and wild turkeys. Woody species can be kept in check by disking, mowing, or selective herbicides.
Firebreaks can be managed for both fallow vegetation and food plot forages. By creating a firebreak 2-disk-widths wide, one half (or side) can be planted and the other left fallow. This can be a very attractive arrangement, depending on what is planted and what the seedbank holds, for species such as cottontail rabbits and northern bobwhite.
Another strategy when creating firebreaks in areas where the seedbank is likely to hold undesirable species is to establish the firebreak the width of a sprayer, not the width of a disk. This allows the use of selective herbicides, whether the firebreak is managed with planted forages or for fallow vegetation.
This firebreak has been planted to oats to provide additional forage during the cool season. The extra width aids in controlling prescribed fires within the adjacent pine stand while allowing adequate sunlight for the food plot.
This food plot was created by disking a firebreak. Notice the sunflower, croton (dove weed), and ragweed which provides forage for white-tailed deer and seed for mourning dove and Northern bobwhite.