GARDENING : WONDERFUL WORLD OF AMAZING GROWTH JUST A WALK AWAY.

Byline: Joshua Siskin

It's amazing how much you can learn about plants simply by taking a leisurely walk around the block, just before sunset in the last days of July, in Sherman Oaks.

In an alleyway, blackberries are ripening in profusion over a chain link fence. The owner of the property never waters the vines to which the juicy blackberries are attached. The berries are an inch in diameter and every bit as sweet as those in the supermarket.

Further down this same alley, also over a chain link fence, more than 1,000 egg-shaped, yellow-orange passion fruits, clinging to their own tendriled vines, are ripening despite no evidence of regular care. This common Valley-grown passion fruit, unlike its more tropical relatives, is inedible for us humans, although it will bring a variety of avian wildlife into the garden. The passion vine's blue-fringed flowers have no floristic equal.

Perfumed hybrid tea roses as large as I have ever seen are growing and glowing on short bushes planted along a neighbor's front sidewalk. The owner cuts these plants very short each winter, nearly back to the ground, and his roses bud and bloom much later than those of anyone else in the vicinity. Severe pruning also means that he has fewer roses than those of us who, each winter, leave our rose canes at a height of 18 inches or taller. But because his blooms are few in number, they are also of magnificent size.

I once saw a nectarine grower in Woodland Hills use this same botanical principle of energy distribution to get baseball-size fruit each year. Almost as soon as they were formed, while little bigger than peas, he would thin his nectarines so that no less than 4 inches separated between any two fruit on a given branch.

Did you ever want a pussy willow tree? A neighbor is growing one in half-day sun. Those soft, silky protuberances are male flowers of catkins. If you find a pussy willow (Salix discolor) stem in a flower arrangement, you can root it in water - just keep the bottom few inches of the stem submerged for a few weeks - and then plant it in your garden.

In the yard adjacent to the pussy willow tree is a sago palm (Cycas revoluta), also growing splendidly in half-day sun. This plant is erroneously named because it is more like a pine, botanically, than a palm. It is the Rolls-Royce of durable plants for Valley gardeners, requiring a minimum of water and fertilizer, and valued at around $25 per inch; in other words, if you have a sago with a trunk that is a foot high, you have a plant worth $300. One of the best retirement accounts is a yard full of sago palm trees, bearing in mind that they grow little more than an inch per year. Even without a yard, you can grow sagos because they make fine container specimens for patio, balcony, or well-lit indoor locations.

Walking north on Hazeltine Avenue toward Fashion Square, two Norfolk Island pines (Araucaria heterophylla) come into view. One is on the east side of the street, and one is on the west. Each leans longingly toward the other, like star-crossed lovers who will never wed. This tendency to lean can be a major problem with the Norfolk Island pine. Its foliage also burns when exposed to full-day summer sun or excessive wind. But when you can give it the proper exposure, and it grows straight, you never will take your eyes off this special tree. It also grows well in containers, both indoors and out.

Three silver maples (Acer saccharinum) are growing in an apartment complex. The silver maple is easily one of the most glorious, if somewhat problematic, trees for the Valley. Its finely cut leaves with the silvery undersides shimmer romantically in the slightest breeze. Yet it grows with remarkable speed, especially when hard pruned, so thin it out conservatively every two years or so.

In a shade garden I see the variegated mock orange (Pittosporum Tobira Variegata) used as a background plant. I never cease to marvel at the resiliency of this plant. It can grow in sun or shade in the virtual absence of water.