once they break above the browse line they take off, below it they get trimmed to a meat ball shape. Once above the browse line the fun begins, seedlings popping up everywhere! pretty easy to transplant when small, over crowding can, and will lead to a massive area that will be barren underneath if care is not taken to allow sunlight to make it to the ground. We rented a "doomsday" machine 20 + years ago, basically a big wheel loader with an 8 foot cutter head on front. Two 4 foot counter rotating blades that chewed through dang near anything in front of it. Machine only went about 7 mph, but it did so no matter how many cedars were in front of it, up to a diameter of about 8 inches. We cut our overgrown areas roughly into thirds, three passes wide, then skip 50 feet and cut three passes wide again. Three years later we cut the next 3 passes wide. We never made the last cut three years later, prices went through the roof for the service, and our funds nver could make it up to the level needed to afford. You can still see the effects, and it worked great rejuvenating the areas to a good thick brows with lots of escape routes, and cover.