GARDENING : Shade-Loving Begonia Has Its Day in Sun

It started with Cleopatra, a rhyzomatous begonia. Mary Sakamoto of Orange Park Acres was captivated by its beguiling shape and intrigued by its charisma. She bought one at a local nursery 10 years ago.

Soon after, she attended a begonia show and succumbed to the lure and fascination of begonias. While she refers to her acquisition of these shade-loving plants as a hobby, her collection contains more than 2,000 different plants and occupies a good deal of her time.

Her collection was one of two gardens toured Friday by participants of the American Begonia Society’s 1995 convention at the Radisson Plaza Hotel in Irvine. Two-hundred begonia fans from America, Japan, Switzerland and Canada gathered to exchange information, view new plant introductions and enjoy the company of fellow enthusiasts.

Convention-goers also toured the garden of Jack and Arlene Hoskins of Yorba Linda, who grow their begonias on two covered patios that also contain myriad tropical plants. Their garden is enhanced by a koi pond and greenhouse.

The convention also includes a plant show and sale, which is open to the public today and Sunday at the hotel. New and rare begonias will be on display, and about 5,000 plants will be for sale from $1 to $6, depending on plant size (3-inch pots to 5-gallon containers). Hours are 9 a.m. to 5 p.m. on Saturday and 8 a.m. to 3 p.m. on Sunday.

Begonias are perennial plants with a reputation of being hard to grow. That’s because they need protection from sun and freezing temperatures, require moist but not soggy soil, and some varieties are very prone to mildew.

But begonia fanciers feel the striking colors, patterns and shapes of leaf forms and flowers are worth the extra effort.

Sakamoto’s house and garden feature a shade house designed by her husband, Ed, to supply her still-growing begonia collection with the precise temperature, humidity and shade they require.

Built of redwood, the 1,500-square-foot shade house consists of potting area, display benches, seating area, hothouse and aviary.

The potting area provides storage space for hundreds of containers, ranging in size from 2 inches to 12 inches. Fifty-five gallon containers hold Sakamoto’s custom potting mix, and there’s ample work room for her to repot the plants, which, during the active growing season, need repotting at least every two months.

The majority of plants are housed on two-tier bench displays. Most of her collection consists of cane begonias, with several dozen showy rex and tuberous begonias. Hanging baskets of various types of begonias and ferns drape gracefully from the overhead beams.

The L-shaped structure also contains an aviary where a half-dozen Bork parakeets fly. The remaining space is a hothouse where begonias that need warmer temperatures are housed during the winter.

An outdoor covered patio at the rear of the shade house also contains hundreds more begonias in pots and hanging baskets of ferns.

Although begonias can be grown in the ground, and some varieties--such as Rieger begonias--are excellent ground covers because of their bushy, compact growth habit and free-flowering, most begonia collectors prefer to keep them as container plants.

“I can’t place mine in the ground because we get Santa Ana winds here,” explained Sakamoto.

She also likes to control their watering and fertilizing by hand-watering each plant according to its soil condition.

Begonias are categorized by their growth habits. The major classifications are cane, rex, rhizomatous, shrublike and tuberous. There are about 20,000 to 30,000 different varieties, and hybridizers are developing more every year.

Cane begonias are easiest to grow because they best tolerate heat. They do well in the ground if they are protected from sun, wind and frost. They’re characterized by stems that grow tall and woody with bamboo-like joints, and many need staking to support their canes and flower clusters.

Popularly called “Angel Wings,” some varieties of cane begonias produce flower clusters that can grow up to one foot across. Flower colors include white, pink, orange, red or color blends. Leaf coloration is also striking, with many bearing silvery patterns.

“The trend now is to develop begonias with as much silver on the leaves as possible,” Sakamoto said.

Tuberous begonias need cool temperatures and are best grown along the coast. They produce showy flowers in vivid colors and are excellent in hanging baskets.

Shrub begonias are distinguished from cane begonias by their soft, green multiple stems. They also have heavily textured leaves, some varieties with a leaf coating resembling felt; others with red or white hair-like filaments.

Rhizomatous begonias grow from a rhizome, a stemlike structure that creeps at or near ground-level. They produce attractive foliage and flowers that appear winter through summer.

Collectors also like to acquire a distinct type of rhizomatous begonia, termed rex, because of its striking bright, multicolored leaves with many different types of foliage patterns. Many have red undersides and dominant silver stippling on the leaf tops.

But their beauty comes with a price.

“Rex begonias are everyone’s favorite, but they can be contrary,” Sakamoto said. “They can die on you.”