Thanks David,
Yeah, I'd read about granite increasing acidity, as well as marble and
limestone too. I've already got a lot of "river rock", a black rock rounded
by the actions of the waves, coming from the coast! as well as slate and
sandstone (these two will be going onto a concrete based path and wall) One
reason I want to use river rock as mulch is that I can intersperse larger
rocks around, which might help hold the smaller ones in place. The problem
isn't so much that they'll fall out of the raised/terraced garden beds, as
the soil level is about 3 to 4 inches below the top of the retaining walls,
but that I've got a very exuberant Staffordshire Bull Terrier, who loves to
run around everywhere. I have to let her run around these gardens, as I've
already fenced off the herb garden from her. Thus the rounded rocks, which
won't be so hard on her paws.

Thanks for your tips on newspaper, I've been saving some for some time, so
should have enough soon. And it'll sure save money! I cleared the weeds a
fortnight ago, but I notice that the front garden (cleared the week before)
is already resprouting weeds. So, for now, it's relatively weed free, and I
intend to keep it that way for a while. I'm yet to lay down some more
drainage and electricity and water cables for a future rock water garden, as
well as below surface drip feed irrigation lines, which will give me an
opportunity to add more compost to the heavy clay.

Once again, thanks for your comments, I think I'll go newspaper instead of
weed mat! I've looked up Curlex, and in Australia, it's a hair product, and
jute is only available for insulation, and rather expensive. Hmm, maybe one
day we'll learn.

Regards,
Casey


"David J Bockman" wrote in message
...
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.