On 21/07/2014 8:46 AM, David Hare-Scott wrote:
pentapus wrote:
I'm considering making some "sculptural" planters out of hypertufa,
Hypertufa is concrete mixed with sphagnum moss and either vermiculite
or perlite. This makes a somewhat lightweight porous container.
(snip)

Thirdly mixing in sphagnum to reduce weight doesn't seem like such a
good idea to me. Eventually it will rot. How about synthetic beads
instead. Vermilculite or perlite should be OK.

Hypertufa always uses some natural material as part of the recipe -
traditionally it's been peat but also coconut fibre has been another
common ingredient used instead of peat.

Usually they are made in a rectangle shape so that they have a similar
shape to aged animal watering troughs.