Prairies are ecosystem types dependent on burning to renew the nutrients and stop primary succession. Another added benefit to burning at this time of year is that it knocks back the cool season, non-native grasses that often compete in prairies. This year we burned a little over 3 acres so far. The now black earth will warm quickly and cause our native grasses and wildflowers to wake up. It is also important to rotate burning to ensure that some areas are left undisturbed for insect larvae and to increase plant diversity.
Prairie fires were common in southern WI because of Native Americans starting the prairies and oak savannah’s on fire to attract wild game to the fresh grass shoots. Lighting fires were more common in northern WI. Prairie plants have extraordinary root systems and are unharmed by fire. On average, there are 20,000 pounds of roots in 1 acre of prairie!!
For conducting a controlled burn, preparation is key. Ensuring you have fire breaks (mowed paths, driveways) is a key component. Burning when the relative humidity is 50-70% and the wind is less than 10 mph is also helpful. A “back burn” into the wind will allow you to create a fire break by having all the fuel burned in the area the fire will eventually head towards. After the “back burning” is done, you can set “flanking” and “head” fires to complete the burn. The 3-acre section shown in the video below took roughly 40 minutes to complete. You will also see the use of a “drip torch”, which utilizes a diesel-gasoline mixture and allows you set set line fires quickly. Other safety equipment used are water hoses, water spray trailers, backpack water sprayers, and flat shovels.
You can see a video of this burn HERE