GARDENING : LITTLE GARDENING IS REALLY `NATURAL,' SO EMBRACE HYBRIDS.

Byline: Joshua Siskin

It is said that righteous have such a deep rapport with nature that they wince at the notion of tearing a leaf from a tree. Better let the leaf fall on its own, since any tampering with natural processes down here on Earth could have significant repercussions up in heaven.

In an attempt to emulate the righteous, some of us would banish from our gardens any product or technology that could somehow be construed as artificial. At first, this seems like an easy challenge to meet. Proper soil preparation, correct light exposure and precise watering can pretty much eliminate most pests from our plants.

And artificial fertilizers - made in huge furnaces that pull nitrogen out of the air and combine it with oxygen to make the nitrate and urea fertilizers that give farmers such phenomenal yields - can be replaced with what winds up at the Hyperion sewage treatment plant and is marketed at every Los Angeles nursery under a variety of euphemistic labels.

Quickly, the idea of so-called natural gardening becomes a somewhat complex, if not ridiculous proposition. Can a Southern Californian grow plants ``naturally'' with water that is imported from hundreds of miles away? Is it natural for us to grow Bolivian tomatoes, Chinese apricots and Japanese plums? For that matter, is it natural for us to grow anything at all in Los Angeles, considering that the people who lived here prior to the arrival of the Spanish were gatherers, not farmers?

The plain fact is that cultivation of crops is a patently artificial enterprise. And because of the art and artifice employed, focus on this all-too-earthy pursuit can easily turn our gaze inward and away from any higher purpose. We egotistically come to believe that the fruits we hold in our hands are the result of our efforts alone. It is no accident that the patriarchs were shepherds, not farmers.

Just because something is natural or original or old-fashioned does not necessarily mean it is good. For instance, there is a movement under way to discredit all hybrid plants. Hybrid plants, it is argued, may produce abundantly, but require noxious fertilizers and pesticides in order to do so. Older plant varieties, while not as productive as hybrids, do not require the same artificial inputs. The anti-hybridists should recall that, for more than 30 years, strains of hybrid wheat and rice have prevented widespread famines from Latin America to India.

In a fascinating conversation (found at http://burpee.com) between George Ball Jr., the owner of Burpee seed company, and Robert Kelly, an English professor at Bard College, Kelly infers from Ball that ``there is now a kind of sentimental, puritanical dislike or contempt of hybrid plants, a sort of notion that you have to go back to the primal stock, that hybrids are somehow wrong and false, like spreading Crisco on white bread.''

Ball - who also markets heirloom, nonhybridized seeds - expands on this theme: ``It's a good example of sophistry. The people who are advancing this back-to-the-original-natural-sources idea are saying that hybrids deplete the gene pool. In fact, hybrids don't deplete the gene pool at all. If anything, they actually contribute to the development of the gene pool because through the process of creating a hybrid you must create new inbred lines, so you're actually increasing the diversity available to nature . . . I'm advocating the use of hybrids because it reduces habitat destruction in the Third World.

``If they use hybrids, they need less of their valuable land and far fewer chemical inputs because hybrids in and of themselves are stronger and yield greater harvest . . . If some fellow has to use 10 acres to produce the crop for the village, he'll clear 10 acres. If he can produce the same yield form two or three acres, that is far preferable because there's less habitat destruction.''

One of the most effective horticultural practices is foliar fertilization, as with the product Miracle-Gro. In the tropics, it is not unusual for plants to absorb certain mineral elements through their leaves; the rain forest air bathes plants in a mineral-ladden mist. Foliar fertilization has proven effective in growing all manner of crops and plants, including cotton, wheat, soybeans, apples, peaches, walnuts, African violets and turfgrass.

Still, in the tropics or anywhere else, nearly all of a plant's mineral intake is through its roots, and standard fertilization practices reflect this fact. The asset of foliar fertilization is in stimulating root growth so that root absorption of minerals from the soil is maximized. The major drawback to foliar fertilization is its short-lived effectiveness. If you wish to fertilize exclusively through a plants' leaves, then you have to do so with every watering - but at one-quarter strength in order to supplement conventional fertilization practices.

Tip of the week: If you're looking for a pear tree that will bear fruit in the Valley, ask for one of the Asian varieties. They do not require as much winter chilling in order to flower and fruit as the common European pear varieties we see in the supermarket. Make sure the ground is not too wet when planting, or the soil will compact around your tree's roots and reduce oxygen availability, leading either to root suffocation or growth of pathogenic, anaerobic bacteria.