William Wolkoff, 100, at the dahlia garden he founded at Bayard Cutting Arboretum in Great River.  Credit: Morgan Campbell

For most of his 100 years, William Wolkoff did not have a green thumb. That is until he turned 79. Since then, the great-grandfather of six has been known as the founder of the largest dahlia garden on the East Coast and the 150-member Long Island Dahlia Society.

“The colors are absolutely magnificent,” a beaming Wolkoff said on an October Saturday as he surveyed more than 1,000 dahlia blossoms in a rainbow of colors at Bayard Cutting Arboretum, a 690-acre state park in Great River. “We started the garden with nine raised beds, 16 feet by 6 feet, and now there are 43.”

For more than two decades, the Brightwaters resident, who also serves as the society’s garden designer, has overseen a team of nearly two dozen volunteers, or “dahliaholics,” as they call themselves. The retirees plant and maintain 300 varieties of plants, ranging from the tiny “ball” dahlia to the giant “dinner plate” variety.

Margaret McGullam of Oakdale basks in the beauty of The William...

Margaret McGullam of Oakdale basks in the beauty of The William Wolkoff Dahlia Garden at Bayard Cutting Arboretum. Credit: Morgan Campbell

“Dahlias are very unique flowers,” said Wolkoff, whose favorite dahlia is a yellow, red-tipped “cactus” variety named “Jessica.” “Every one of them says, ‘Look at me!’ I love giving them away and seeing the faces of the people, since they are so spectacular.”

Peaking in later summer and early fall, dahlias bloom from midsummer until the first frost. After the first hard frost, Wolkoff supervises the volunteers as they begin the painstaking process of winterizing the dahlias’ tuberous roots so they can be replanted in the spring.

Master gardener

Wolkoff was a builder by trade, and he is the source of birdhouses, pergolas and trellises at the Dahlia Garden at the Bayard Cutting Arboretum.

An award-winning master gardener trained at Suffolk County’s Cornell Cooperative Extension in the science and art of gardening, Wolkoff is one of nearly 85,000 certified Extension Master Gardeners who volunteers across the nation, according to the Extension Master Gardener program. The program, which for the past 50 years has been supported by the U.S. Department of Agriculture, promotes sustainable gardening by educating the public.

A contractor by trade, Wolkoff constructed a trellis in the arboretum’s dahlia garden around 2001 with built-in benches and topped with colorful birdhouses that forms a backdrop for one end of the garden. Near the center of the garden’s meandering paths, he built a pergola, with seating, about a decade ago, and a wooden tower encircled by a bed of petite border dahlias. A “grow room” that he built adjacent to the garden cultivates dahlias from seedlings or tuberous roots.

Caroline Kiang, who founded the Master Gardener program at Riverhead’s Cornell Cooperative Extension of Suffolk County in 1977 and was its director until 2013, remembers well having Wolkoff as a student.

“He came to my program in 2006,” recalled Kiang. “He’s a gentleman and a kind person. He’s very knowledgeable about growing dahlias, and he’s eager to teach others how to do it; he never gets tired of explaining how to grow dahlias.”

Kiang said Wolkoff excelled in the five-month competitive program that trains students in a broad spectrum of subjects, including plant nutrition, botany, plant propagation and pruning, and diseases and insects that affect plants.

In 2015, his contributions to the promotion of dahlia culture were recognized with the prestigious President’s Award by the American Dahlia Society, a nonprofit group composed of more than 70 independent dahlia societies across the United States and Canada.

Post-retirement bloom

William Wolkoff, a master gardener, does some pruning. Almost two dozen volunteers...

William Wolkoff, a master gardener, does some pruning. Almost two dozen volunteers tend the 43-bed dahlia garden. Credit: Morgan Campbell

Born in 1922 in Bay Ridge, Brooklyn, the young Wolkoff graduated from the former Haaren High School in Manhattan and enlisted in the U.S. Army during World War II, briefly attending Furman University in Greenville, South Carolina, to study aeronautical navigation, as required by his military orders. Before being deployed to Germany, he married his high school sweetheart, the late Marie Grande, in 1944.

After returning from the war a year later, Wolkoff found work as a plasterer and the couple settled in Islip, raising four children. By the early 1950s he and his brother-in-law had formed a contracting company, renovating such prestigious landmarks as Carnegie Hall.

It was not until Wolkoff retired at age 62 that his interest in dahlias bloomed after a longtime friend introduced him to gardening. “He showed me how to plant dahlias at my house,” Wolkoff recalled. “I was surprised they survived.”

As his passion for gardening grew, Wolkoff joined the Long Island Horticultural Society, based at Planting Fields Arboretum in Upper Brookville, and the Westbury-based Mid Island Dahlia Society, which tends a dahlia garden at Planting Fields.

By the late 1990s, Wolkoff proposed building a dahlia garden at Bayard Cutting Arboretum to then-director Brian Feil. At first, his idea hit a brick wall because of fears volunteers wouldn’t keep up the garden, Wolkoff explained. Soon, though, the director “saw the benefits of the garden, and he let us expand it year by year.”

Kevin Wiecks, the current director of Bayard Cutting Arboretum, said the William Wolkoff Dahlia Garden is a “major draw” to the arboretum. At the Long Island Dahlia Society’s annual Dahlia Exhibition and Photo Show on Sept. 3 and 4, both the arboretum and the event attracted nearly 4,500 visitors.

He credited Wolkoff and his volunteers, one of whom is his daughter, Phyllis Wolkoff, 67, a Realtor who lives in Brightwaters, for the success of the garden and exhibition.

‘Elder statesman’

Wolkoff shows off a dahlia called "Dr Les" during a picnic...

Wolkoff shows off a dahlia called "Dr Les" during a picnic at the garden in 2007.  Credit: Newsday / Bill Davis

“Bill is the elder statesman of the dahlia world and the driving force behind LIDS’ [Long Island Dahlia Society’s] commitment,” Wiecks said. “It is like no other, and I belong to a lot of different plant societies. One thing you don’t always see with volunteers is follow-through and commitment, and the Dahlia Society is a hardworking group that gets things done.”

Joseph Lysik, 71, the Long Island Dahlia Society’s garden director, agreed that Wolkoff is a results-oriented leader. After mentioning to the centenarian that a particular dahlia bed was receiving too much sun, Lysik suggested they erect a shade cloth to protect the plants.

“The next day he [Wolkoff] had it all worked out,” Lysik said. “He looked up ‘shade cloth’ on the internet and priced out what it would cost. By the next week he bought the shade cloth and clips to attach it to the scaffolding. .  .  . His mind is always thinking about changing and improving things, and he acts upon them immediately.”

As a former member of the Cornell Gardeners, a volunteer gardening community, Wolkoff said, he also tended a dahlia garden at Cornell University’s Long Island Horticultural Research and Extension Center in Riverhead.

Mark Bridgen, director of the center and professor of plant sciences at the university’s School of Integrative Plant Science, the Horticultural Section, met the “dahlia expert” at the horticultural research center in 2004.

Wolkoff, Bridgen explained, volunteered with the Long Island Dahlia Society to put in a dahlia garden in 2005.

“He was about 80 at the time, full of energy, and an amazing, really smart guy,” Bridgen said, adding that he also built a pergola in the garden and a shed featuring a “green roof” that is topped with succulent plants.

Bridgen admits he did not know much about dahlias before Wolkoff taught him about the “tedious process of winterizing dahlias and how to grow larger dahlia blooms.” Yet, Bridgen said, the most valuable lesson Wolkoff taught him was the “importance of being kind to others.”

“I learned that I should pay it [kindness] forward,” he said. “William is a booster shot of niceness.”

Long Island Dahlia Society

Joseph Lysik, left, the Long Island Dahlia Society’s garden director,...

Joseph Lysik, left, the Long Island Dahlia Society’s garden director, at the arboretum with Wolkoff in 2007. Credit: Newsday / Bill Davis

•To become a member of the Long Island Dahlia Society (longislanddahlia.org), send your name, address, phone number, email address and $20 annual family membership fee to Long Island Dahlia Society, P.O. Box 66, West Sayville, NY, 11796.

•Even if you don’t have a green thumb, seasoned professionals will teach you how to grow a successful dahlia garden.

•Optional hands-on experience is available at The William Wolkoff Dahlia Garden at Bayard Cutting Arboretum, bayardcuttingarboretum.com.