No kidding..Round up becomes inert very quickly, not an issue. That's why, even here in Ontario where every herbicide is banned except it, it's still allowed
I had the trees and scrub professionally removed from under my hydro lines back on the 4th of Aug...the machine mulched everything down to the ground. The pic below shows the regrowth in the past 5 weeks. The off shoots coming back on the willow are already almost 2' high (the spade is 3').
If I don't use Round-up to control the re-growth....I'd have to brush cut this back every 3-4 months or it will be back in full force by next summer.
There is another alternative to stop re-growth permanently, it's illegal. PM if your interested.
http://i125.photobucket.com/albums/p...psriqtmb3f.jpg