I started bush-hogging at 8:30 this morning and went for 9 hours with about 30 minutes off for lunch.
Technically, I have a John Deere rotary cutter. "Bush Hog" is the registered trademark name for the popular tractor implement made in Selma, Ala., but nothing better describes how the cutter chews up undergrowth. My hog will take down 3-inch saplings without any problem.
For cleanup around the trees and for areas that are too steep for the tractor, I use a Stihl blade trimmer (seen on the cutter). I can handle saplings up to 2 inches with it.
Another 8 hours and I should be hog clean.