Black plastic is very bad for the soil. Do not use it. There are newer
landscpae fabrics to use instead.
I used to design special nature trails and native plant gardens for
several California Park Departments and one of the best path material for
high or low traffic is decomposed granite.
The path needs to be graded correctly, excavate 4". The first three inches is
for you compacted base rock. The last inch is for the decomposed granite
mixed with a binder. The path must have header (border) the least
expensive is 3 ply redwood or plastic (kinda manufactured looking but
durable - I never use it but you might). 3 ply is used for all curves,
2x4 redwood header for all straight runs. I have gone to 4 ply. on the
curves lately looks very nice and lasts even longer.
When the material first goes down it looks like gravel, in time with
people walking on it, the granite compacts to make a nice hard walking
surface. D/G drains nicely, is not muddy and if prepared on base rock
lasts quite a long time. For a nice effect you can also use flagstones
or any 1" or greater depth stone in the D/G too. If there is lots of
public traffic though - stick to simple D/G it comes in three colors
gold, grey and somethimes red.
Mattison FitzGerald
Landscape Designer
http://www.rhinodev.com/M