Indian summer: an ideal time to burn oak woods

Although we were not able to burn this fall (too busy getting ready to plant the East Basin), the last week has been ideal burn weather. This is the period commonly called "Indian Summer" in the upper Midwest.

What is Indian Summer? This is a period of warm, sunny, dry weather that follows several sharp cold periods. The cold periods bring about the senescence of native plant species and hasten leaf fall. The following warm period is ideal for burning prairies, wetlands, or woods.

Indian Summer is is an especially good time to burn a bur oak woods, because the leaves of this species get dumped all at once over a period of a week or so. (White and black oak leaves tend to hang on most of the winter, gradually coming down.) When the bur oak leaves fall they are already well "cured", and because of their curls, do not fall flat on the ground. Thus, fire carries well. It is especially valuable to do a fall burn if you are planning to plant the understory. The burn opens up the forest floor so that the planted seeds get to the soil surface.

Spring burns can of course also be done, especially if one is not planting. However, for woods burns early spring ephemerals may already be up and will be knocked back by a spring burn. This is never a problem with a fall burn.

According to William McClain, an ecologist with the Illinois Natural History Survey, Native Americans generally burned in the fall, and this may be one reason why this season is called "Indian" summer.

Here is a brief history of Indian Summer weather.