WHEN THE GOING GETS TOUGH, THESE ORCHIDS GET GROWING.

Byline: >JOSH SISKIN

A humble plant grower and librarian, who wishes to remain anonymous, has the most floriferous orchid I have ever seen.

There must be a hundred flowers adorning the single potted plant she has placed atop the check-out counter in the library where she works. Can there be a more charmed existence than hers, I wonder, being surrounded by flowers and books? Anyone who says you can't have it all should contemplate the benefits of such a life.

The orchid in question is an Oncidium (on-SID-ee-um). Although the orchids most often seen -- the Phalaenopsis or moth orchids encountered in supermarket flower departments -- are in the pink-to-lavender spectrum, along with some pure whites, Oncidiums are most famous for their uncompromising yellow color.

Oncidium flexuosum and Oncidium reflexum are commonly referred to as dancing dolls or dancing ladies on account of their flowers' resemblance to grande dames in crinoline ballroom gowns. The individual Oncidium flowers are small by orchid standards, no more than 1 1/2 inches in size, but they are generously distributed on highly branched inflorescences at this time of the year. The blooms of the library orchid are pure yellow in their billowy skirts, with some brown blotches and brown dots painted on the parts above.

But now consider this: the library Oncidium was grown on a shaded outdoor patio in Encino. That's right. Not in a greenhouse with climate control or close to the ocean where the mild weather would be classically conducive to its growth.

Orchids, it turns out, are surprisingly tough tropical plants. Because of their astonishing beauty, we may think of them as delicate creatures. Their ecology should teach us otherwise. Most orchids are epiphytes, a fancy word for plants that live upon other plants. Epiphytes include bromeliads, staghorn ferns and certain cactuses. They spend their entire lives suspended on branches or nested in crotches of tree limbs, their roots dangling in the air or covered with moss and hydrated by the misty atmosphere alone. The constant companion of epiphytes is drought, evidenced by their leathery foliage.

Expert plant growers will tell you stories about how they killed many orchids before finally learning how to grow them. Nearly always, orchids are killed by excessive water or fertilization. Orchid root media consists of bark or osmunda fiber, hinting at their dislike of standing or excessive water. A 20-20-20 fertilizer is recommended, to be applied at half strength about once a month.

For the popular moth orchids, light exposure is best through a good-size, north-facing window. Oncidiums, on the other hand, require the brighter exposure of an east window. Oncidiums, epidendrums, and cymbidiums can be grown outdoors in protected locations.

Oncidiums, together with Cattleyas, are among the most drought-tolerant -- or moisture-sensitive -- orchids, owing to their pseudobulbs, which serve as water storage organs. Keep them on the dry side, allowing roots to dry between watering applications. In winter, they can go for up to two to three weeks between waterings.

Do you have any ideas on how to deter neighborhood cats from using my garden as a cat box?

>GERMAINE CHAPMAN,

NORTHRIDGE

A motion sprinkler may offer the solution you seek. The sprinkler comes on when a cat is in the vicinity, operating on the same principle as a motion detector light. Upon activation, water pulsates from the rotary sprinkler for three seconds. Motion sprinklers are also effective at deterring intrusive deer, coyotes, raccoons, squirrels and rabbits. Motion detector sprinklers are available at home improvement centers in the $50 to $70 range.

Tip of the Week: If you are looking for a colorful and durable container plant for full sun exposure, consider Bougainvillea "Raspberry Ice." As a rule, bougainvilleas do not succeed as container plants over the long term, but "Raspberry Ice" is the exception. This bougainvillea has green and cream variegated foliage, which, when new, is flushed with pink. Bracts are deep red. "Raspberry Ice" will persist in a 12-inch-diameter or larger container for up to 10 years.