"Philip Lewis" wrote in message
du...
yup... pond liner, layers of newspapers, weed barrier, concrete, etc.

you want a barrier that they won't grow through.

Things to consider:
Where is the runnoff going to go if you use a less permiable barrier?

Into the neighbor's garage. :-)

With anything "permanent" think about local codes. (since this is a
property border)

Probably a good reason to use some sort of paving tiles instead of little
stones. But, if the neighbor's amenable to whatever is done, why worry? If
one neighbor or the other sells the house, the new owner can be consulted as
to whether they'd like the stones/pond line/whatever left in place, or if
they'd prefer a sumac hell.