Dr. William Ackerman beside C. leucantha at the National Arboretum (Richard Mohr/Courtesy Photo)
Gardening columnist

There was a time when guys wore too much plaid, had too much hair and drove cars the size of tennis courts. It was called the 1970s.

It was also a period of wickedly cold winters — this might seem a cruel taunt in the midst of an infernal summer — but this frigidity brought its own misery. William Ackerman was a plant hybridizer at the U.S. National Arboretum at the time, overseeing a scientifically valuable collection of camellia species and varieties. Two successive harsh winters devastated these big, lovely, evergreen shrubs. By the spring of 1978, he was able to gauge the full damage: Of 956 specimens — many collected by explorers in Southeast Asia — only 15 had survived. Similarly, camellias perished in gardens across the metropolis.

The calamity was to shape the rest of his life: Ackerman died July 6 at the age of 89, but he left the world with a raft of new camellias bred to endure temperatures down to 15 degrees below zero. Short of a new ice age, which doesn’t seem the prevailing climatic trend, camellias are safe now in the Washington garden, thanks to Bill Ackerman. Moreover, he has extended the range of a flower associated with the old South as far north as Nova Scotia.

Thirty-five years ago, many gardeners around here thought they had lost one of their most special plants: Camellias had all the big-leafed evergreen beauty of rhododendrons, hollies and Southern magnolias, but with the added bonus of large, showy waxy blooms, in shades of red, pink and white. They like gardens with partial shade and need a sheltered spot in winter to avoid wind damage; thus the shade garden becomes an asset. Most of all, they flower at a time of year when much of the garden is bare.

Varieties of a species called Camellia sasanqua bloom in the fall into winter. The showier, more iconic C. japonica varieties flower in late winter into early spring.

If the plant has a fault — other than the fact that flowers in February can get zapped by a freeze — it’s that a blossom that looks so fragrant is scentless. Sasanquas can have a perfume, but it is slight and musky to many noses.

Ackerman was working on breeding more fragrant varieties when the freezes changed the focus of his work.

His breakthrough in cold-hardiness came with a species named C. oleifera. Two named varieties, Lu Shan Snow and Plain Jane, survived the freezes at the arboretum in Northeast Washington. Oleifera’s flowers aren’t very decorative, and it is grown in its native China for its seed oil. Its popular name is the tea-oil camellia.

Ackerman also used another species, C. hiemalis, in his efforts. Often his crosses would be as complicated as he needed them to be to create the garden plant he wanted. For example, a variety named Winter’s Snowman has as one parent Plain Jane and the other a seedling he raised by crossing C. sasanqua Narumigata and C. hiemalis Shishi-gashiri.

This is nerdy stuff, but the point is that it takes four to six years for a seedling to bloom, and thus to be evaluated. When you consider that he introduced some 50 cold-hardy varieties, winnowed from thousands of hand-pollinated seedlings, you get a sense of his passion for this quest and the number of years he spent on his work.

Ackerman grew up on a dairy farm in New Jersey and attended Rutgers University, where he met his wife, Kitty. They were married for 64 years.

In the early ’50s, working for the Agricultural Research Service, he moved to the agency’s plant introduction research station in Chico, Calif., where he evaluated tree fruits and nuts, including peaches and pistachios.

It wasn’t until he came to the agency’s research station near Beltsville, at Glenn Dale, that he began his work on camellias, along with Japanese iris and other ornamental plants.

When he retired from the arboretum in the early 1980s, this merely allowed him to spend more time working on cold-hardy camellias at his seven-acre farm in Montgomery County, where he had a few greenhouses to raise his seedlings.

Most of his introductions bloom in the fall and early winter, including his Winter series. Winter’s Beauty is a compact, upright shrub with soft pink blooms; Winter’s Dream has a stronger pink, semi-double flower and is more vigorous and upright. Winter’s Snowman is white with anemone-type flowers, suited for mass planting as a narrow hedge.

His later Ashton series included Ashton’s Ballet, with rose-like flowers in two-tone pink; Ashton’s Snow, with white semi-double blooms that last from early November to late January; and Ashton’s Supreme, which is covered in deep lavender-pink blooms in the fall. He was particularly proud of Ashton’s Ballet, Kitty Ackerman told me.

The form and habit of his plants was particularly important to him, she said. Previously, when camellias were grown in greenhouses for showing, the focus was flower form, but Ackerman wanted his camellias to function as handsome garden plants and selected varieties for their leaf color and gloss and the shape of the shrub.

“He tried very hard to get people to appreciate camellias for their landscape potential,” she said.

He also collaborated with other hybridizers, notably Clifford Parks in Chapel Hill, N.C., who also worked on cold-hardiness. “He concentrated on oleifera and I concentrated on varieties with japonica,” he said. “He was very enthusiastic about his work and very anxious to communicate and to collaborate with people.”

Margaret Pooler, who succeeded Ackerman and another prolific hybridizer at the arboretum, Don Egolf, said that “you can see the great strides” they achieved. Egolf, who died in 1990, is perhaps best known for his work on crape myrtles. “They took a plant and totally changed the way we can use it,” said Pooler.

Ackerman, in his book “Beyond the Camellia Belt,” said that in plant breeding “there are no guarantees. Perhaps it is the failures that make the successes so much sweeter.”

Bill, we thank you.