Yardsmart: Pebble plants are irresistible

I think I've hit rock bottom with pebble plants. These finicky plants are basically doomed to failure, but every time the garden center receives a shipment of lithops, lapidarias or fenesterias, I lose all self-control. Those tiny "living stones" are just too cute to pass up at less than $3 a piece.

These succulents are known as mimicry plants, which evolved in the dry southern African climate. They are small and designed by Mother Nature to look like real stones camouflaged by color and angular shapes. Lithops resemble elephant feet. Lapidarias are blue, smooth-skinned and wholly geometric. Fenesterias are named for their tubular form and feature a "window" at the top to let in light. Don't fret about learning these names because they are rarely sold by their botanical nomenclature. Their labels usually say "mimicry succulents."

I once visited a renowned lithop grower, an old fellow who lived amid a warren of greenhouses. He had learned the secrets of starting this genus from seed. I had never seen so many stages of growth, from specklike seedlings to overflowing mounds. There are more than 40 species and countless varieties that resulted from this fellow's pollination experiments. They range in color from green to brown, but always resemble natural stones.

Though this fellow mastered this one genus — making them seem easy to grow — they are anything but. It seems that if I water them, they melt down. If I don't water them, they still melt down. Ditto for too much sun, too little sun, too much cold or not enough cold. These are some of the most specialized plants, and if environmental factors aren't right-on, they shrivel.

My friend Clark Moorten, a desert-garden authority, recommends that I keep a misting bottle near the lithops. "If you just can't stand it and must water them, wait a week, then spray them with the mister," he says.

Misting is important because much of southern Africa, from the east coast of Natal to the pointed Cape Horn, experiences a long dry season. In the brutally dry west coast of the Atlantic, the dry season is even longer. However, heavy coastal fogs travel inland, often at night, to lay down a thick layer of dew. Plants here have evolved to utilize this airborne moisture during a long drought. It explains why regular watering regimes during a dry season are a killer. These plants really do need mist. And most important, that mist should not be treated city water, with all its fluoride, chlorine and minerals. Use distilled water, and the mist won't leave behind ugly white mineral buildup.