I'm a newbie, and would like your suggestions about mulching my raised
garden beds, containing mostly palms, as well as some other tropical plants.
The beds I'm referring to are about 1 metre wide and raised above a
concrete patio. They are held in place with 85 cm high retaining walls,
behind which is a drainage system consisting of aggy pipes set inside a bed
of scoria, with the whole lot wrapped up in weed mat.

The soil is a heavy clay below (the bottom 60 cm), with about 15 cm of
chicken shit flavoured loam on top, which comes to about 9 cm below the
height of the top of the bricks, to prevent rocks being knocked out onto the
patio. One of my aims is to be as conservative as possible with water, given
that I'd established a tropical garden just prior to the introduction of
Victoria's water restrictions.

To this end, along these garden beds, I want to lay rock mulch as one of my
strategies. With the laying down of rock mulch, I've been told that 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 using rock mulch?

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. Should this go just below
the weed mat, from one plant to the other, so that water only drips onto the
plant roots? (I'd like to keep the irrigation system hidden.)

Also, does anyone have any ideas on the proximity of rocks to plants? I hope
to grow moss on some of the "shadier" rocks, but there are also 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. Or will they?

Finally (questions, questions!), as well as "river rock", slate and
sandstone, I also want to lay "slate mulch", but a friend warned me that it
might be too sharp for my dog's feet. I don't know whether a vet who doesn't
know how sharp slate mulch is would be any better qualified than a gardener
who doesn't know how sharp a rock would cut a dog's foot, but I've already
prevented my dog from dropping doggie doos in the herb garden, and don't
want to restrict her any more. Yeah, I know, don't lay slate mulch, but are
there any "softer or more rounded" varieties?? Either the slate mulch gets
laid, or doesn't get laid......

I hope I haven't asked too many questions, so I'll thank you in advance for
your replies!

Regards,

Casey
www.twistedirony.com