IN THE GARDEN POMEGRANATE TREES IDEALLY SUITED TO VALLEY CONDITIONS.

Byline: JOSHUA SISKIN

USUALLY WHEN people think of exotic fruit trees, their thoughts turn to tropical species such as star fruit, cherimoya, miracle fruit, banana and sapote. These trees make you think of rain forests, lots of precipitation, humidity and acid soil - conditions which are the opposite of those that prevail in our part of the world. Yet all of these trees may be grown in the Valley, albeit with special soil preparation and sun protection.

Enter the pomegranate. Here is a fruit tree which is far better-suited to the dry climate and alkaline soil of the Valley than tropical trees, yet the pomegranate tree may nevertheless seem equally exotic to Valleyites - if only because of its virtual absence from our gardens.

For years I observed a hedge of pomegranates growing along the road leading to the horticulture department at Pierce College in Woodland Hills. It seemed as if these trees got little - if any - water or fertilizer, and yet they fruited abundantly year after year.

Although pomegranates will produce crops on alkaline or clay soil and without summer irrigation, their production will increase on well-drained sandy soil and with a good soaking once or twice a month in hot weather. A maximum of 1 pound of actual nitrogen per tree per year, applied in late January, is the only fertilizer required. Flowers are reddish orange and highly ornamental.

Without constant vigilance, your pomegranate tree is more than likely to turn into a large multitrunked shrub, since the plant puts out uninterrupted sucker growth. However, such shrubs will devote most of their energy to vegetative growth (shoots and leaves), producing smaller harvests than single-trunked trees. Trees are harvested in the fall as soon as the fruit has sized properly, which is typically at a diameter of about 5 inches. Fruit left on the tree after maturity is reached or following a fall rain is likely to split.

Single-trunked trees will reach 20 feet, while trees left to sucker freely will top out at 10 or 12 feet and, planted in a row, will make an unorthodox screen or tall hedge.

By the way, the word pomegranate comes from the French for seedy (grenate) and apple (pomme), a reference to the hundreds of seeds that constitute a pomegranate fruit.

TIP OF THE WEEK: Speaking of names, you might almost think the sycamore got its name from the fact that it is ``sick more'' than any other tree. In truth, all of our California native sycamores (Platanus racemosa) are infected with the anthracnose fungus to one degree or another. This disease turns leaves crispy brown long before they drop off in the fall. Anthracnose is also responsible for the angular, contorted, sometimes even horizontal growth of sycamore limbs. These trees are also plagued with powdery mildew fungus, appearing as a cottony white fuzz on leaves. If you want to grow a sycamore whose trunk is guaranteed to grow straight and that is resistant to both anthracnose and powdery mildew, you will want to select a variety of the non-native London plane tree (Platanus x acerifolia ``Columbia'').