GARDENING : RARE MOMENTS OF HORTICULTURAL DISCOVERY IN FULL BLOOM.

Byline: Joshua Siskin

The memorable moments in a person's life may be few, but among them, without a doubt, are those moments of horticultural discovery.

I remember the first time I saw a princess flower (Tibouchina urvilleana); it was stretching for light in a too-shady North Hollywood backyard. It only had a few flowers, but they were of a regal violet-blue that I have never seen before and have not seen since. And then there was that African tulip tree (Spathodea campanulata) on Missouri Avenue in West Los Angeles, with its orange-red chalices for blooms; I had never seen such a gorgeous street tree and wondered why it was not more widely planted.

Or, speaking of chalice flowers, how about the incredible Allamanda vine that grows over a huge arbor outside a UCLA medical building in Westwood? Its large, deep yellow cup flowers simply do not look real; seeing them will leave an indelible impression on even the most casual observer.

Getty's poppy

For some reason that I do not fully understand, pictures of poppies become especially fixed in the mind's eye. At this moment, on the slope between the San Diego Freeway and the Getty Center, there is a large patch of blooming Matilija poppies (Romneya coulteri). These are affectionately referred to as ``fried egg'' flowers because of their large yellow centers that are surrounded by crepe paper white petals.

No plant is better suited for erosion control than the Matilija poppy. Its ropy rhizomatous roots grow deep and spread rapidly. The more this poppy is watered, the longer it flowers and the faster it spreads. However, it can subsist on winter rain alone. Because of its invasiveness, the Matilija poppy is more suited to industrial than residential sites, unless it's the only plant you want to have around the house. It has a mild fragrance and attractive dusty blue, sharply cut leaves that stand up well in vase arrangements.

Although it is difficult to eradicate once established in the ground, the Matilija poppy is somewhat tricky to propagate. Seeds may be germinated by placing them under fallen pine needles, but you will probably have better luck digging up rhizomes, with leaves attached. Plant the rhizomes in one-gallon containers and leave them in the shade until new growth is evident.

The Theodore Payne Foundation, 10459 Tuxford St., Sun Valley, is a wonderful location to view Matilija poppies up close. It is where many of us were introduced to these and other California native flowers. One of the foundation's prize specimens is Harford's island busy poppy (Dendromecon rigida ``Harfordii''). Indigenous to the Channel Islands, this shrub has attractive blue-green leaves and yellow flowers. It would look nice in combination with the native blue-leafed manzanita (Aretostaphylos glauca), an arborescent shrub with smooth, stunning reddish bark.

Three weeks ago, I was privileged to see an oriental poppy (Papaver orientale) bloom for the first time. In ``The Standard Cyclopedia of Horticulture,'' L.H. Bailey writes that ``no plant is more brilliant in late spring or early summer than the oriental poppy, with its large flowers, silken petals and flaming colors.'' Unfortunately, you will not find blooming oriental poppies in local nurseries but will have to grow them from seed. (Oriental poppy seed packets should be available at nurseries.) Because they are slow to develop, plant oriental poppy seeds now to be sure you will have flowering plants next year.

Many colors

The original oriental poppy, which comes from Armenia, has orange-scarlet flowers that are 4 to 12 inches in diameter. Black markings are found at the base of iridescent petals. Hybrids in salmon and pink are also encountered. The plant is a perennial, and can be divided during its dormant period, which is in late summer. Its leaves have stiff hairs and resemble those of certain thistles, so make sure you plant it where no one on a weed patrol could mistake it for an undesirable plant.

Stirling Macoboy, author of ``What Flower Is That?'' calls the fragrance of the oriental poppy flower ``acrid and somewhat disturbing ... for these and other large poppies are the source of opium and its derivatives.''

I want to thank Ed Gooley of North Hollywood for planting oriental poppies. Gooley carefully tended these plants for many months at the West Valley Occupational Center in Woodland Hills. Just before they bloomed, Gooley became ill and was not able to see them in their glory. I hope you see this, Ed, and wish that the description of your poppies will brighten your day.

Tip of the week

Gaura (rhymes with Laura) is a plant that will bloom all summer long in full sun with little water. This year, a magenta-flowered cultivar has been added to the traditional white. Native to the Southwest, gauras grow to 4 feet tall and spread over the ground like a Mexican primrose, to which they are botanically related.