Here in the mixed-grass prairie, the talls grow just above the meadows, the mids next, and then the shorts on the hilltops. Gotta remember that multiple burns are required to allow the native plants to begin to outgrow the invaders, especially Kentucky bluegrass. After that, recommendations for livestock producers are about once every four years. Trouble is many are not set up for rotational grazing. I have one plot I have burned nine times and the natives are flourishing, but no cattle use it. And my target species, smooth brome and Western wheaatgrass, are still common. One of the keys is to burn when the bluegrass is in full flower and the roots are lowest in nutrients. Another problem that develops here under idle conditions is the movement of low prairie species upslope because of increased soil moisture. For example, some say it takes at least 20 burns to get buckbrush (Symphoricarpos) back to the low prairie that it originally flourished in. Season long grazing is another problem to be avoided if prairie restoration is the goal as is use of herbicides as they are not species specific.