Keeping It All Connected

Keeping It All Connected

Plein Is Recharging the American Horticultural Society

The Osage orange tree (Maclura pomifera) at River Farm is at least 200 years old. It is on the Virginia Big Tree Register.

The Osage orange tree (Maclura pomifera) at River Farm is at least 200 years old. It is on the Virginia Big Tree Register.

His passion for the natural world was sparked at age five in 1963 when he spent hours exploring the woods and creek behind his family home in Annandale. Scott C. Plein, chair of the Board of Directors of the American Horticultural Society (AHS), headquartered in Mount Vernon, delighted in catching frogs, toads and garter snakes. He was awed by nature’s wonders when he watched a frog swimming in the creek.

At age ten he started mowing grass and as a high school senior, hired his first employee, a business that grew into a lifelong love of plants and landscaping. His interest in nature and landscaping evolved so that today he champions native plants and counts as one of his heroes, Aldo Leopold, a 20th century Wisconsin naturalist who wrote A Sand County Almanac published in 1949. “We must understand how the natural world interacts with human habitation,” says Plein and “to survive, we need nature to be healthy and need humans to support it.” He also admires the late Edward O. Wilson, a Harvard University entomologist, who wrote extensively on biodiversity, stressing the interconnection of all plants, animals and micro-organisms on earth. “We must understand how it all works together,” urges Plein.

Plein founded KT Enterprises in 1976, a landscape development firm and an affiliate, Total Development Solutions, companies that service home builders, developers and commercial contractors in the Washington metropolitan area. He is the founding principal of Equinox Investments, a real estate investment firm begun in 1999. He loves to tout his cornerstone project, Villages of Piedmont, which he believes balances human needs and natural habitats. The development includes a 380-acre park with seven miles of trails, called Leopold’s Preserve, protected by a conservation easement. 

Plein founded the White House Farm Foundation, based in Northern Virginia and the Shenandoah Valley. On his 270-acre White House Farm near Luray, Virginia, he grows native trees and plants on 60 acres. “We believe in striving for a healthy ecosystem, which encompasses wise use of natural and human resources,” says the foundation’s website.

Why AHS?

In 2020, AHS listed River Farm for sale for $32.9 million, a proposal that raised the specter of developers buying and transforming the property. The listing divided the Board of Directors, spawned intense local backlash, mobilized elected officials’ opposition, threatened legal action and resulted in some board member resignations. Selling River Farm was “absurd,” Plein argued then. After the tumult subsided, a reconstituted board canceled the sale and began what Plein calls “re-inventing ourselves.” 

He joined the Board in 2021 and became chairman in 2022, he says, “because I believe in this place. It’s an iconic property and it should be saved and open to the public.” River Farm can “exemplify good gardening,” he contends, by nurturing both traditional landscaping and landscaping with native plants. Pointing to the wooded area, he insists that the property “can be a good example” of blending traditional landscaping with ecologically-friendly gardening and stewardship.

He hopes to “help AHS find its place” and “influence where horticulture goes,” to especially involve more young people in gardening and conservation. “We’re the national horticultural society, so our number one priority is to be the best at representing every aspect of horticulture and continuing to encourage all Americans to discover the benefits and joy of gardening,” he told The American Gardener magazine in January.

Plein invites the local community to “get involved, to help make it great.” Though AHS is a national organization, he sees River Farm as “part of the neighborhood, a special asset for the community.” Noting that visitors pay no entrance fee, locals can always help financially and build community and political support for River Farm, he notes.

Among Plein’s many civic activities, filling two single-spaced pages of his resume, are serving on the board of the Potomac Riverkeeper Network and Mason Housing. He has been involved with the Northern Virginia Building Industry Association, National Association of Industrial Office Parks, Northern Virginia Transportation Alliance and the Northern Virginia Conservation Trust. He’s a member of Ducks Unlimited and the Virginia Native Plant Society.

Plein lives in Falls Church. He has two adult sons, one daughter and two grandchildren. He’s very glad he “fell in love” with River Farm.

River Farm 

River Farm, at 7931 East Boulevard Drive, Alexandria 22308, is on the Potomac River. Its 18th-century-style manor house has offices and event spaces. The property was the northernmost of George Washington’s five farms and once home to Tobias Lear, Washington’s secretary. 

Founded in 1922, AHS moved its national headquarters to the site in 1973. The 25-acre property has formal and natural gardens, woodlands, a meadow and a children’s garden.

The gardens are free and open to the public. Visit

Sept. 23 Gala

AHS will celebrate its 50 years at River Farm with cocktails, dinner and dancing at a gala on Sept. 23. This year’s theme is “Simple Pleasures of the Garden,” featuring renowned interior and garden designer Charlotte Moss. Visit for sponsorship and ticket information.