"I'm a generalist who likes to have a hand in everything and a handle on the bigger vision of an organization," he says, which translates into "set priorities, establish goals, and carry them out.
"You have to have a clear idea of what you're trying to do before you can do it."
One thing's very clear. In 2013, anyone heading up a public garden - or orchestra, theater, or museum, for that matter - has to deal with a range of issues that may strike some as more marketing than mission. But they are critical to survival.
How to attract a larger, more diverse audience. How to appeal to young people. How to simultaneously honor tradition and embrace change. And, yes, how to make money - or break even, or not lose too much - without sacrificing the organization's integrity.
"Public gardens realize they have to fully engage the public to stay relevant," says Casey Sclar, a former Longwood entomologist now serving as executive director of the 500-member American Public Gardens Association.
He adds: "And have you ever talked to a cultural institution that says, 'We have all the money we need'? Public gardens need public support."
Public is a word Downing uses frequently when discussing his new job, which comes with a $7.8 million operating budget and 75 full- and part-time employees. As in: "We want to make Mount Cuba a more public public garden."
First, he must answer a more basic question: How to get word out that Mount Cuba even exists.
The public has had little opportunity to visit the gardens at this former Copeland estate in Hockessin's hilly countryside, even after the 2001 death of Pamela C. Copeland, widow of Du Pont Co. chairman Lammot du Pont Copeland.
Visitation has been limited to docent-led, reservation-only tours and the Wildflower Celebration - a single day of the year when anyone could drop by. Starting this year, there will be open visitation days on Fridays and Saturdays from April 19 to Nov. 9, a big change for Mount Cuba, but a small step compared with other gardens.
"We want to get our mission, education, out to a wider audience, so people can come and see our native plants and learn about them," says Ann Copeland Rose, Mount Cuba board president and Copeland granddaughter.
Downing is realistic, and excited, about the task at hand. "A lot of these estates are in various stages along the way to transitioning from family estate to public garden. . . . We're much closer to the starting line than most of the others.
"A desire for openness starts the process," he says, adding that wherever that process leads, "great care must be taken not to lose any of the things that make this place special."
That would include the naturalistic gardens, native plant collections, conservation efforts, research and education, and what fans describe as "the intimacy of the Mount Cuba experience."
Downing enjoys the bucolic isolation of this place, having grown up "an outdoorsy kid" in now-famous Newtown, Conn.
Mom was a real estate agent. Dad was a product manager - cereals, Jell-O, Log Cabin syrup - at General Foods. "There's probably still some Jell-O in my mom's closet," he jokes.
Sports were big. Downing was a soccer player and Nordic ski jumper in high school, which included two years at Deerfield Academy, the Massachusetts boarding school. Divorced, he still loves to ski and has taken up mountain biking with his two daughters, 9 and 11.
He also runs five miles a few times a week, though he notes of the terrain around Mount Cuba, "running in Delaware will shorten your life."
At Trinity College in Hartford, he majored in economics, chosen for both its big ideas and practicality. A desire to more fully explore big ideas drew him to Yale Divinity School, for a master's degree in religion, which is not as incompatible with economics as it may sound.
"With economics, you ask, what do people value in worldly terms? In religion, you look beyond the material," he says.
After graduation came some reckoning. An academic teaching career seemed unrealistic due to the research requirement, "and you needed to have five languages at your disposal, a couple of them dead," Downing says. "I was well-suited to begin my career waiting tables."
Although he did a bit of that, he also taught philosophy and religious studies at two local colleges. Then came a five-year stint teaching at, then managing, the Kaplan Education Center in New Haven, which offers student prep courses for standardized tests.
Kaplan encouraged Downing's entrepreneurial efforts to build up the business, an experience he enjoyed and was good at. Later, he would apply that approach to the nonprofit world.
For-profits and nonprofits "are both trying to grow and expand and improve their effectiveness, with one important difference," he says.
"In the for-profit world, you do stuff to make money. In the nonprofit world, you get money to do stuff and your impact is your goal.
"You're not measured by how much money you've got but by what you did with it," he says.
Contact Virginia A. Smith at 215-854-5720 or firstname.lastname@example.org.