Jane G. Pepper, who transformed the Pennsylvania Horticultural Society into a national model for "greening" neighborhoods, parks, and public spaces over three decades of leadership, will retire as president after the 2010 Philadelphia Flower Show.

An emotional Pepper, 63, told the staff yesterday at a meeting in the society's Center City offices, even as she announced six layoffs and 5 percent pay cuts for senior managers, 10 percent for herself.

Pepper makes $200,000 a year. A national search for her successor will launch in June.

"I have been so lucky to have this job. I will always treasure it," she said in an interview yesterday.

Pepper's departure will be huge. With her trademark pixie haircut, boldly colored blazers, and round glasses, she is the unmistakable public face of the horticultural society and its best-known endeavors: Philadelphia Green, the urban-gardening component, and the Flower Show, the nation's oldest and most prestigious.

While the Philadelphia show reliably draws about 250,000 visitors, raises $1 million for the society, and pumps $30 million into the city economy annually, several smaller shows around the country succumbed to the economy this year, and others are struggling.

Even the venerable Massachusetts Horticultural Society is in debt and disarray. In December, it auctioned off valuable botanical-art books to raise cash, and this spring, for the first time in more than a century, it canceled its annual flower show.

"You're lucky to have a Jane Pepper in Philadelphia," said Betsy Ridge Madsen, the Massachusetts society's president.

On Pepper's watch, PHS has grown dramatically in mission and reach. That is reflected in staff (28 when Pepper took over, 111 now), operating budget ($1.6 million in 1980, $21 million today), and programs, whether workshops on growing vegetables and planting trees, "green" teacher training, or botanical tours of England, often led by Pepper.

During her tenure, PHS's membership has doubled to about 15,000. It has forged partnerships with city and state government, foundations such as Pew and William Penn, and corporations like Home Depot and Peco. Its programs have moved beyond Philadelphia to the suburbs and elsewhere in Pennsylvania and the country.

PHS has "cleaned and greened" 5,000 vacant lots in Philadelphia and recently advised Baltimore; Cleveland; Albany and Rochester, N.Y.; and Pittsburgh on how to manage theirs. In December, it paired with the nonprofit Keep America Beautiful to offer workshops, training, and Internet seminars to that organization's 1,000 affiliates across the country.

One of the biggest changes Pepper has brought about involves broadening the society's base to include gardeners like Doris Gwaltney. With a $30,000 PHS grant and other support, she single-mindedly set about cleaning up a filthy, drug-infused park in her West Philadelphia neighborhood.

"PHS used to be about Main Line ladies sipping tea on the veranda, little pinky fingers, you know. Now they have all kinds of people, little people," said Gwaltney, who was featured in Edens Lost and Found, a 2006 PBS series about environmental rebirth in cities.

She called Pepper "a classy lady who's down to earth and doesn't mind getting her hands dirty. This woman has jet burners on her, always zipping around."

All that zipping around helps raise public awareness of the society, said marketing director Lisa Stephano, who has worked with Pepper for 28 years. "People didn't understand back in the '70s and '80s the impact that the horticultural society has," she said. "I think they do now."

Much of that is due to Pepper, who carefully crafts the PHS message and image, though some joke that her staff already has cultlike zeal when it comes to "greening."

Over 182 years, PHS's mission has evolved from one of horticulture as an end unto itself to plants and gardening as a means to an end. This is reflected in a brief mission statement: "PHS motivates people to improve the quality of life and create a sense of community through horticulture."

Such vision wasn't the plan when Pepper arrived in the United States from Scotland in 1967; she planned to return in a few months to a secretarial job in London. Instead, she met and married "the love of my life," G. Willing "Wing" Pepper, who encouraged and supported her in her career until his death in 2001.

Pepper's interest in such a path was sparked during a stint working at Haverford College, whose campus is an arboretum. She embarked on six years of horticulture study at Temple University, the University of Delaware, and Longwood Gardens' graduate program.

Pepper's PHS association began in 1976 when she volunteered at the Flower Show. She quickly became a protege of the society's dynamic president, Ernesta Ballard, who started many of the initiatives Pepper and others have built upon.

Ballard hired Pepper in 1979 to do PHS's public relations. Pepper moved up to executive director in 1981 and the top job in 1985.

Paul Meyer, director of the Morris Arboretum in Chestnut Hill and a Longwood classmate of Pepper's, remembered with amused hindsight the consternation at PHS when Ballard retired.

"Everybody was wringing their hands, wondering, 'How are we ever going to replace Ernesta?' " he said. "The opinion was that maybe Jane wasn't quite ready for the top job, and then, after a search, they said maybe she is the right one."

Early doubts were soon dispelled. "Jane has provided extraordinary leadership," said John K. Ball, chairman of the PHS board. "For her, this has not been a job. It's been a full-time commitment to the work."

Pepper's successor need not have a background in horticultural education, Ball said, "but he or she must have leadership experience . . . in whatever field they work in, and a love for gardening and greening."

Pepper, typically, already has retirement plans: "Dogs, garden, bike, visiting family in the U.K.," she said. That would be two standard poodles; deer-protected, fenced-in gardens at her Media home; a Trek hybrid bike; and a large extended family.

But first, one more year running the show. "We've got a ton of things to do," she said.