in my backyard are 3 rows of roots from my neighbors trees running about 20' in length. where it enters my yard the roots are exposed. this year little saplings are popping up all over my backyard. the mower takes care of them, but still... i was thinking circular saw and slice. the problem is that circular saws have a 7" blade, of which only 1/2 that length is exposed. so basically i can only slice 3.5" deep. i guess i can cut a 'V', take a small chunk of the root out then slice again at the deepest part of the V? maybe use a saw zall/reciprical saw? but i need to dig out one side of the root so that the blade doesnt get bent by dirt. Other easy/practical (ie: not nuke from above or burn the tree down) ways of severing the roots in my backyard?