Hypertufa is fake

Real tufa is not readily available, but you can easily make hypertufa - a fake tufa - from a mix of Portland cement, perlite, peat moss, and water. Peat moss helps the finished rock hold moisture, perlite makes the rock light and porous, and the Portland cement and water bind the whole thing together. Use this mix also to mimic those ancient stone troughs which the British are so fond of using as planters.

To make hypertufa, mix the dry ingredients in the ratio of two parts cement to three parts each of perlite and sifted peat moss. Then slowly add only enough water to make the mix workable.

Now don a pair of rubber gloves and start piling the hypertufa into a rocklike shape. If you're creating a trough, build it with a form. Use boxes - or bowls, for round planters instead of troughs - made of such materials as cardboard, styrofoam, or plastic.

For a free-form outer surface, pile the hypertufa mix at least two inches thick over the top and sides of a form. For a more finished outer surface, line the inside bottom and sides of your box or bowl with the mix. For a finished surface inside and out, use two boxes or bowls that you can nest inside each other.

Cover everything for a day to cure, then remove the form(s) and work the semi-hardened surface to your liking with a coarse file or wire brush. Drill drainage holes with a masonry bit. Again cover your creation with plastic, and leave it covered for two weeks to harden. Before adding potting soil, leach lime from the concrete by temporarily plugging the holes and every day for two weeks letting fresh water sit in the container for a day, then dumping it.

The planter can stay out even in winter, so choose plants that can take cold and drought and have interesting leaf colors and textures all year round.

Besides hens-and-chicks, other plants suitable for hypertufa planters include cerastium, thyme, carnation, rock cress, dwarf crested iris, and, of course, saxifrages, whose very name means "broken rocks."