Burning a Wisconsin prairie in the winter!

I’ve discussed the problems with fall prairie burns in our part of the country. 

So if fall burns are so difficult, winter burns must be impossible?

Yesterday (December 18, 2018) we had a very successful winter burn at Black Earth Rettenmund Prairie. How was that??

The November/December weather had not been good. No sun, mostly cold and cloudy, little snow, not much rain. We had given up doing any burns. But then, December 15-18 a dry air mass arrived, with dew point 20-22, clear sunny weather, strong south wind, and temperatures reaching the low 40’s (F) by noon. It certainly wasn’t Indian Summer, but we had burned with these sort of conditions last spring. Fire, of course, makes its own temperature, so if the fuel has good prairie grass and the dead fuel moisture content is favorable, it should burn.

Fortunately, our burn crew was available. We decided to do it.

One problem with a winter burn is you need water, and the pump at our well had been drained for the winter. Since the temperature was slightly above freezing, we primed the pump and filled all the water jugs and backcans. (At the end of the day the pump was drained again and all backcans emptied and the spray wands brought indoors.)

Kathie had already mowed the fire breaks, so the prairie was ready to burn. The map at the end of this post shows the burn area. Amanda ran the burn.

The weather continued favorable. We met at BE Rettenmund at 11:30 AM for a noon start. We had eight crew, all experienced, and one trainee. 

Because of the south wind, we started at the north end of the North Unit. One crew moved west and south, the other east and south. Each person had a radio, so the two crews could keep in touch.

One problem with burning this prairie is that it is a long, narrow unit with two moderate hills that break up the wind. So a south wind is often a southwest or southeast wind, often at the same time on different parts of the burn unit. Fortunately, the prairie is surrounded on most sides by crops, which at this time of year have been harvested. The bare fields show well in the photos.

The North Burn unit (on the right) is almost finished burning. The head fire at top will be coalescing with the back fire from the north.
Jared is starting to light the Saddle.

Kathie and Denny are preventing the fire line from creeping over the lane into the crop field.
Creep was a problem and they had to monitor it the whole way.
It is unlikely the field would burn, but it would be embarrassing if it did!
Note the solid black burned unit.

Burning the Fesenfeld Road embankment. The trail from the entrance is visible snaking up the hill.
The fuel in the lower, planted, Gateway Prairie (a former alfalfa field) below the top is not as good as the
fuel of the remnant prairie above. 

 After the whole burn was completed, the crew returned to the North Unit and burned the Fesenfeld Road embankment, which is separated from the burn unit by the peripheral lane.

A satisfied crew.
Denny, Jared, Amanda, Tiffany, Chris (kneeling, with two drip torches)
Susan, Josh, Kathie. (Tom, who drove the truck, behind the camera).