GARDENING : BUCKTHORN OFFERS EROSION PROTECTION, PRESERVES PRIVACY.

Byline: Joshua Siskin

At long last, there is a plant whose character as an evergreen shrub or small tree is unimpeachable. The Italian buckthorn (Rhamnus alaternus) may be used as a background plant, as a hedge or screen, as a topiary subject or patio tree, on slopes for erosion control, as a fire-retardant species and to attract wildlife.

The Italian buckthorn is native to the maquis of southern Europe. The maquis is the Mediterranean equivalent of our chaparral, a plant community composed mostly of slow-growing evergreen shrubs and trees that subsist entirely on winter rain.

Like so many other drought-tolerant species - from common geraniums to cactuses - the Italian buckthorn will grow more quickly if it is regularly watered. Just make sure you avoid planting it in poorly drained soil where its roots may rot from standing water.

I first encountered Italian buckthorn during a sojourn in Israel. It was growing as a tall informal hedge in a small town near Jerusalem. I was immediately struck by two unusual aspects of this plant's appearance. First, the tip of each leaf pointed skyward, regardless of its location on the plant. In most plants, only young, developing leaves have such a vertically pronounced orientation. Second, the color of each leaf was a rich, glossy green, a color not typically seen in the foliage of a tall hedge, much less in a drought-tolerant plant. Plants from dry climates commonly have gray or dull green leaves. Altogether, the plant had a clean, thrifty and self-sufficient look.

The Italian buckthorn will eventually grow up to 20 feet tall, and individual plants will also spread 20 feet unless pruned or planted more closely together. Since the Italian buckthorn can take either full sun or partial shade, it would make a welcome alternative to the Indian laurel fig (Ficus nitida), which is currently the most popular local hedge plant despite the fact that it destroys sidewalks and driveways and requires constant pruning. The Italian buckthorn, a deep-rooted plant that is native to a climate like our own, will neither lift sidewalks nor demand persistent shearing in providing the qualities sought in an evergreen hedge.

The Italian buckthorn has berries that attract a plethora of birds. Its geotropic roots stabilize hillsides. Although its flowers are nondescript, the perfection of its foliage make it one of the most elegant evergreens in the world.

There is a California native plant, suitable for a tall hedge, with a lush leaf not quite on a par with the Italian buckthorn, but distinctive all the same. This plant is the Pacific wax myrtle (Myrica californica). It can also grow to 20 feet tall and has purple fruits that are irresistible to birds.

Ray Frerking is a student of garden design who writes of his efforts to create an English garden in the town of Rosamond, a high-desert community midway between Lancaster and Mojave in the Antelope Valley. He seeks suggestions for developing such a garden.

The Antelope Valley is in Sunset climate Zone 11, which is too cold for many of the common ornamental plants found in Los Angeles. An English garden contains a variety of perennial plants with outstanding flowers or foliage but not a lot of wood. You might wish to incorporate lavender into a Zone 11 garden since it is cold-hardy; its many cultivars offer a range of interesting flowers and leaves. Many penstemons are also cold-hardy and have flowers in the red, pink and purple range. I would also include certain cold-tolerant ornamental grasses, with their feathery flower spikes and fountain shapes, in a high-desert garden.

The best illustrated book of plants for the high desert, or any California locale, is a volume by Bob Perry titled ``Landscape Plants for Western Regions: An Illustrated Guide to Plants for Water Conservation.'' This book is available for around $45 through several of the Internet book vendors and is worth every penny. Hundreds of plants are explained and displayed in excellent color photographs. The Theodore Payne Foundation (818-762-1802) is another outstanding source for plants, seeds and books needed to create a high desert garden. Located in Sun Valley, the foundation has everything you need to know about landscaping in any of California's more challenging soils and climates.