Re: Old Shrubs
Short of herbicides, I agree with keith.
Soak the ground to make it soft and easy to dig, then dig those suckers out. You don't have to worry about every speck of root, just the major root ball and major tendrils. Anything that goes under the sidewalk can either be cut at the sidewalk OR you can undermine the sidewalk a little (4" - 6" ) to remove them a little more, just be sure to repack the soil as you place it back in the hole under the sidewalk.
There are times when mechanical help in the form of a truck or winch might be necessary, but for the majority of things, merely soaking the ground well will do the trick. If you are beyond the age or ability to dig the shrubs out, then hiring one of the neighbor kids or a lawn service for the task would be the next best thing.
I suffer from CDO ... Its like OCD, but in alphabetical order, LIKE IT SHOULD BE!!!