I put down black fabric....the type they use on the highway road bases...thick heavy poly tight weave....
I use it to cover my raised garden in the winter to keep weed seed from blowing into the zone.
That works ....it gets pulled up every year. OTOH....I put same down as a barrier all around the house
trying to do a xeriscape thing. I now have native grass that has completely grown on top of the
weed barrier because it did NOT get pulled up every year and so to answer your question @pinnah, it may
or may not work, depends upon your application. Stuff likes to grow on top of it, now if I desire to
change the technology...what a mess I have to undo the grown over fabric.