IN THE GARDEN THIS SUMMER BROUGHT OUT THE HEBE JEEBIES.

Byline: JOSHUA SISKIN

For more than 15 years I had been watching them, those demure shrubs with decorous leaves yet few, if any, flowers. In truth, even the leaves had problems, as new shoots would die back the moment they began to grow.

But this June, all of a sudden, those long-watched shrubs are covered with flowers and their neat rows of shiny, succulent leaves are without blemish.

The shrubs in question are known as Hebe (HEE-bee), a Greek name that means ``bloom of youth.'' Many times I had thought of removing these shrubs from the garden because of their chronically diseased look. Yet their highly polished, neatly aligned foliage was unlike anything I had ever seen and their few flowers, looking like a collection of Fourth of July sparklers, were exotic enough to merit giving them another chance.

There are several possible reasons why plants, after many years in the doldrums, suddenly show their true beauty. The first and most important is size. In all the research done on flower production, the size of the plant, more than any other factor, has proven crucial. If a plant is slow-growing; is heavily pruned on a consistent basis;or is stunted because of chronic disease, poor soil or lack of water, the critical amount of foliage needed to induce flowering may simply not be present. (It is helpful to remember the hormones that promote flowering in a plant are found primarily in its leaves.)

Even where a plant has reached flowering size, it may bloom sparsely due to weakness brought on by insect pests or disease. In such a case, control of the pest or disease in question will allow the plant to show its garden worthiness once again. It happens quite often that a pest is suddenly brought under control by the buildup of natural predators in the garden or by changes in weather patterns over a period of years. As mysteriously as a pest or disease appears practically overnight, it may just as mysteriously disappear.

For years, Hebe had been the victim of a fungus blight throughout Los Angeles. Now, this year, when it is almost impossible to find Hebe anywhere, the shrub seems to have made a comeback. It is worth growing again, if only one plant at a time, to see if it will indeed continue to prosper.

The Sunset Western Garden book lists more than a dozen species of Hebe, all of which come from New Zealand, that will grow in Valley gardens. Hebe flowers are blue, lavender, purple or pink. Plant sizes range from dwarfs no more than 2 feet tall to substantial shrubs that grow up to 6 feet in height.

Five years ago, I planted a seed of the California spice bush (Calycanthus occidentalis). Just a few days ago, it produced its first flowers. I had considered removing this plant several times because of the puny growth and burnt leaves it showed during its first years in the garden. The fragrance of its leaves and its California native lineage earned it a reprieve.

I am glad I kept this plant in the garden. Its flowers are burgundy red, spicy like its leaves, and resemble small water lilies. Incredibly, the foliage that had been burnt every year up until this one is perfectly green.

The California spice bush is a deciduous plant that can be grown either as a background shrub, informal hedge, or small tree. Unpruned, it will grow to more than 10 feet tall. It is supposed to need regular water, but I have never given it much. Although it is exposed to afternoon sun, its roots are well-shaded, a circumstance that will typically reduce the amount of water a plant requires.

TIP OF THE WEEK: One of the most pleasing summer flowers is the dahlia. Dwarf to giant types are available. Dahlias grow from tubers, which, to last more than a year, must be lifted in the fall and covered with sand, sawdust, peat moss or perlite. Store them in a cool place during the winter before planting them outside again the following spring. If you want a real garden curiosity, consider planting a tree dahlia. Tree dahlias grow to over 20 feet tall. They die back to their roots in the winter but do not have to be lifted like their smaller cousins. They are also perennials that will regrow the following spring.