The 24 year old 12 hp C125 Wheehorse here has been cutting waist high grass for about half its lifetime. Now that I'm here most of the time, without the annoyance of that hideous nighmarish torture-thing called a "job", it won't get that high, I hope, except in places that are soaked by this year's torrential rains to the point where I can't get to them.
The first thing is, it has to be dry- if it's not, forget it. The second thing is third gear in low range is about the most you can do, and at this speed, you will feel most hidden rocks with the steering in plenty of time to stop. And of course, the mower deck is set as high as it will go. The real problem is that the blades are like 15 inches each on the 42 inch deck, and when the grass is long enough to bridge the 15 inches, it doesn't all get sucked up into the path of the blades. So, you cut in one direction first, and then, if you can, cut in exactly the opposite direction before the stuff stands up again. This little tractor has never ceased to amaze me with what it can do. It has now been demoted to part-time work, as last month I bought a New Holland TC26DA to cut most of the big patches of grass (though the monsoons prevented me from using it for several cuttings because the ground was too soft.)