Hypertufa is a cast “rock-like” material
which can be used for relatively inexpensive bonsai
pots and slabs for plantings. It looks like rock, can
be cast into almost any shape, is very lightweight and
also strong enough to withstand the freeze/thaw cycle
of most northern climates. The American Rock Garden
Society uses the following basic recipe to create alpine
troughs. They can be textured anywhere from very smooth
to a rough rocky look for a “natural pot”.
Upon reviewing this page, it is highly
recommended to visit The
Trough Garden page by Alan Grainger and the
Design page. The same link is provided above.
- Dry Portland cement
- Builder’s sand, traction sand, “sandbox” sand; can
have relatively large stone particles mixed in (in
fact, adds to the texture!)
- Peat moss, sifted to remove larger lumps and foreign
- “Normal” garden variety perlite, sifted to remove
- Pure vermiculite. Many seed starters also
contain some kind of compost and/or peat mixed in.
This will not work!
- “Shredded” fiberglass fibers (to add strength)
- Concrete Dye (optional)
All of the following mixtures are used
the same way. Mix all of the dry ingredients well, and
then slowly add water until you get a thick “mud pie”
texture. Shape (pour into a mold) and let cure. Curing
can take 1 to 2 months! Molds can be made several ways.
One which I think would be fairly easy would be to make
an inverted “bowl” shape in sand, and then line the
sand with plastic (like a heavy garbage bag). After
putting the wet hypertufa into the mold, cover it with
the plastic and let it cure covered for a few days.
Then uncover it for the remaining cure time. After it
cures, you can rough it up with a wire brush, or cut
it with a saw. Add drainholes as required using a screw
driver or drill. If you want a rough finish, you may
need to “melt” any exposed fiberglass using a propane
torch or a candle.
- 1 part cement, 1 part sand, 2 parts peat
- VARIATION 1
- 1 part cement, 1.5 parts sand, 1.5 parts peat
- VARIATION 2
- 1 part cement, 1 part peat, 1 part perlite, 1 part
- VARIATION 3
- 1 part cement, 1 part peat, 1 part vermiculite
- VARIATION 4
- 1 part cement, 1 part sand, 1 part peat
American Rock Garden Society recipe
I personally have not used any of these
mixtures, although I did see a demonstration of this
in October of 1993, and I saw the cured slabs in November
of 1993. Keep in mind that the finer the mixture, the
smoother the texture of the finished product.