Finally: Good weather for controlled burns

We’ve been burning so much this spring under marginalweather conditions,  that it was a surprise yesterday to have ideal weather for our burns. Not only did we complete our regularly planned burns, but we were able to re-burn many of the units that had not burned well in the February and March burns. As Amanda said: “The day everything burned REALLY well”.  At 10 AM the temperature was over 50 F and the R.H. was 42%. By mid afternoon it was 70 F with RH around 30%.

Of course it was April 24, very late for us to be burning, but you have to take what you are given. Fortunately (?), the very cold April kept almost all of the plants underground, so they were protected from fires. The few species that had already shown a few shoots above ground should have no trouble re-growing from dormant root-stock.

Why do we burn with marginal weather? Most of our burns involve oak savannas or woodlands where burn conditions are often iffy. However, it is so important to get these burns done that we do them when we can. The idea is that we can create reasonable peripheral black lines and get as much of the interior burned as possible. Then, if better conditions arise later, we can go back and re-light areas that did not burn well. And this is what we did yesterday.

Unit 10 savanna burn of Feb 27-2018. Although black, there is a lot of unburned thatch. 

The same savanna after the re-burn on Apr 24, 2018.
Complete combustion, as shown by the white ash

In contrast to savannas, prairie burns can generally be very successful in marginal weather conditions, provided the fuel is fully cured and the dead fuel moisture low enough. The same day that our savanna burn was not very successful, the nearby prairie burned very well.

No thatch left after this burn of Feb 27, 2018