I find that old carpeting (available free from carpet stores.  They're happy
to have someone take away the old stuff that they've pulled up from jobs)
laid down around the hives works just great. I weigh it down with bricks at
the corners.  It last forever!
At first I put it colored side up, but the colors were so dreadful that I
turned it upside down.  The jute backing is a nice, natural color and blends
with the landscape.  It cuts very nicely with a razor. I find that strips
about 4-5 feet wide do the trick, all around, in front and back and
inbetween.
 
No need to use Roundup
 
Faith Andrews Bedford
Ivy VA and Tampa