This method for making
hypertufa can stand up to
Seattle rains and Minnesota
winters.

Preparation

Choose a mold of a desired size and shape: square, rectangular, round, or oval. We used an 11 x 13 x 14-1/2-inch plastic dishpan -- the finished trough slides out easily, and the mold is reusable. We also used a foam box liner (rescued from the trash; 9 x 15 x 5 inches) to make a cold-hardy container. In this case, the mold remains part of the trough; the foam insulates the hypertufa and helps plants survive cold winters. If you choose a metal or wood mold, line it with a sheet of plastic or a garbage bag before shaping the hypertufa in it.

Start with a small container; progress to larger ones when you feel more comfortable with the process. If you prefer to make a birdbath, use a garbage can lid for a mold.

Work on the floor of a well-ventilated area where it's OK to make a mess, such as the garage or basement. Spread out a tarp or large sheet of plastic to make a washable work surface; clean up with a hose.

Troughmaker June Skidmore recommends "aging" hypertufa (encouraging moss growth) by painting the outside of the trough with yogurt. Keep the trough moist and shaded until moss develops.