pulled out many trees, big + small.
Larger ones did have problems with dirt stopping the burn. Several solutions;
1; let it lie around through the summer, then shake off the dried earth by lifting and dropping it or some such.
or
2; after the rest of the brush is burned off, roll the unburned rooty part out of the coals, bonk the baked earth off, and roll it back. the next day all is ash.
or
3; if you're in a hurry, carry it to the garage and blast the dirt out with a high pressure cleaner.
Congrats on the new grapple!