It all depends upon how you wish to treat the soil, or how you wish to grow
your plants. For example, the Gotelli Conifer Collection at the National
Arboretum is mulched in granite gravel without a weed barrier. The drainage
is decent, and as the granite slowly decomposes its adding acidity to the
soil. It supresses weeds somewhat, and those that do spring up are easily
pulled. How weedy is the soil to begin with?

Perhaps a good compromise would be to lay down a generous layer of newspaper
or cardboard first, then the gravel on top. The paper barrier will block
weeds for several years if not heavily worked, and as it decomposes it
enriches the soil somewhat. Other biodegradable weed barriers include Curlex
and jutte blankets...

Dave

"Litl Fish" wrote in message
...
oops, I must have posted an off post topic?

"Litl Fish" wrote in message
...
I'm a newbie, and have only looked at this site when I've had specific
problems, as we're still busy landscaping our new house. Now I'm up to
the
stage where I have to pay a bit more attention to the soil, having
installed
adequate drainage behind the retaining walls. Once that's completed, I
intend to create rock gardens, and intend to use rock mulch on the
garden
beds, instead of the more traditional types of mulch. We live in the
southern part of Australia, where we've just come from a drought, but
still
have water restrictions, and summer is just around the corner. One of my
aims is to be as conservative as possible with water, given that we've
already established a tropical garden.

With the laying down of rock mulch, I believe I'm supposed to lay weed
mat
first, on top of the soil, and then lay the rocks on top of this. Is
this
the best way to attain my ambition of retaining moisture below the soil?
And, other than the weeds that will inevitably grow in between the rocks
in
time, is this a good way to reduce the amount of weeds? I'll be
installing
drip-feed irrigation hoses just below the surface, to assist in
providing
enough water to the plants. Also, there will be a "dry" rock garden
creek,
in which I'll introduce a level of fall to direct additional rainwater
to
these plants. (I'll lay butyl below the surface of the "dry creek" bed
to
assist the water runoff to the plants along the way).

Also, does anyone have any ideas on the proximity of rocks to plants? I
hope
to grow moss on some rocks, but there are a lot of palms and birds of
paradise, tree ferns, birds nest ferns and other tropical plants that
might
not appreciate the proximity of sun-heated rocks near their trunks.

Thanking you in advance for your replies!

Casey.