GARDENING : IT TAKES TIME, BUT TALL TREES MAKE A COOL NEIGHBORHOOD.

Byline: Joshua Siskin

In 1935, Bonnie Myers, then 23, got married, bought a piece of property in Studio City and built a house on it. (The property, a double-size lot, was purchased for $800 and the house cost another $3,200).

Today, Myers gets frequent calls from real estate agents who want to list her home of 61 years. She isn't interested. Myers, you see, lives on what may be the most beautiful street in Los Angeles.

Cantura Street, a heavenly byway, is only three blocks long. But when you stand at one end of it and look into the distance, you'll think that it goes on forever. It runs parallel to and immediately south of Ventura Boulevard, between Rhodes and Vantage avenues, just west of Laurel Canyon Boulevard.

Those three blocks of Cantura Street are the envy of everyone who visits them - on account of the magnificent California sycamores that arch overhead, growing up from the parkways on both sides of the street.

The city could use more such parkways.

We live in a desert that requires shade to be tolerable, if not habitable. According to Myers and other residents of Cantura Street, their closely planted parkway sycamores cool summer temperatures around their homes by 10 to 20 degrees. Coast live oaks - like those planted in the city of Claremont - are the only other trees indigenous to this area that can produce such an effect. As long-lived native trees, they are the most appropriate species for planting in Los Angeles parkways.

But the air conditioning created by these trees - albeit a steady antidote to the protracted inferno we call summer - is as nothing compared to the aura of permanence which they create. The sycamores of Cantura give that neighborhood an identity that is sorely lacking elsewhere in our fair city. Because of these trees, Cantura Street is a place to come home to.

Bonnie Myers says when she moved to Cantura Street, the sycamores were already 15 years old, which makes them 75 years old today. In an era of instant gratification, it is sacrilegious to talk about embarking on 75-year projects. Yet only by embarking on long-term projects - and parkway tree planting is the ideal example of such - can a commitment to a place be truly expressed. Buildings may come and go, whole streets of houses may be torn down and put up again, but the trees remain.

The word ``sycamore,'' incidentally, is derived from the Hebrew ``shikma.'' The shikma, which appears in the Bible, is actually a kind of fig tree, Ficus Sycomorus, that is native to the Middle East. What we call a sycamore tree has no botanical relationship to the biblical sycamore, although the leaves, bark and growth habit of the two trees are similar.

Joanne Venditto of Canyon Country writes: ``We have a large slope in back of our house and we need some ideas for it. It is steep enough to make it difficult to walk on (I slide all the time). We hesitate to plant a lot of ground cover because our water bill will go sky high. Some people have told us to plant some big trees. The neighbors have pine trees and eucalyptus. We are located in a canyon, and snakes come down form time to time.''

Not all ground covers are thirsty. Trailing rosemary, Rosmarinus Officinalis ``Prostratus,'' should not require a soaking more than twice a month. Coyote brush, Baccharis Pilularis ``Twin Peaks,'' requires even less water than that.

Myoporum is a third ground cover you should consider. It requires a bit more water than the first two but performs admirably in the heat. You might also consider red apple ice plant, Aptenia Cordifolia, which is one of the fastest-growing ground covers, but will require at least twice-weekly watering if planted in full sun in your area.

Many herbs will grow nicely on your slope - thyme, lavender, marjoram, oregano and myrtle are all drought-tolerant. To make the slope more manageable, construct terraces with the help of railroad ties. Prior to planting - to prevent erosion before root systems have developed - put down jute netting (with U shaped staples) to hold the slope in place.

To save water - especially on a slope, where runoff from conventional sprinklers is a serious problem - you should consider installing a drip irrigation system. Myoporum, for example, responds particularly well to drip irrigation; three weeks ago I saw it blooming spectacularly in the 120-degree heat of the Judean Desert near the Dead Sea. If you are set on sprinklers, use the slow-moving, gear-driven rotaries; avoid spray sprinklers and impact/impulse rotaries.

I would think twice before planting tall, fast-growing trees, having witnessed many fallen pines and eucalyptuses that were planted on steep slopes. If you want trees, plant slow-growing natives such as coast live oaks. At the new Getty Museum, hundreds of oak trees have been planted on the relatively steep slope that runs down to the San Diego Freeway.

As for the snakes, you should consult with an ornithologist and find out how to attract certain birds of prey - which feed on snakes - to your property. Remember, though, that snakes are also beneficial; they play a major role in keeping down the gopher population.

Gardening tip: Wait until the fall before planting - on a slope or anywhere else. The middle of October is the most favorable time for planting ground covers, shrubs and trees.

MEMO: Joshua Siskin's column appears every Saturday. He welcomes questions from readers. Write to him in care of the Daily News Features Department, P.O. Box 4200, Woodland Hills, Calif. 91365-4200. You can also reach him through this on-line mailbox: JoshSiskinaol.com. Topics of general interest will be discussed in the column.