One garden was not enough for Barb and Charlie Green. Once they started getting their hands dirty, they kept on going, carving out new sections of their landscape to convert into beds.

But unlike some gardeners who expand to create more of the same, the Greens are always game to try something very different, often inspired by an idea or object they've picked up during their travels.

Take their knot garden — a very formal garden style most often seen on the grounds of grand British estates. The Greens saw an elaborate knot garden in London, and decided to try a smaller version at home. Knot gardens are rare in Minnesota home landscapes, and require a lot of precise hand-pruning, but that didn't deter the Greens. Barb researched designs based on a classic Celtic knot, Charlie drew a template, then Barb chose dwarf barberry and boxwood in three different colors — and fussed over them until they finally formed the distinctive fluid shape.

"It took me a couple years," Barb said, but the impact has been worth it.

"You don't see them in most people's back yards," Charlie noted.

Then there's their labyrinth garden, a spiraling walking path of pavers accented by groundcover plants and decorative tile made by an artisan they discovered in Jerusalem.

"We had seen labyrinths in various places," Charlie recalled. "It just struck me it would be an interesting, fun thing to have in the back yard. Labyrinths are calming and peaceful," he said. Both of them find it relaxing to walk their labyrinth, although Charlie admits it's hard for him to turn off his gardener's radar when he's doing it. "You're supposed to be in a meditative state, and then, 'Oops! There's a weed.' "

Garden 'follies'

Usually one of the Greens gets an idea, then they work together to make it happen. "Charlie does all the hard labor, and he has very good design sense — he can visualize things in his mind better than I can," said Barb. "I tend to be the person who picks the plants."

Some gardens are more his or hers. "The knot garden is my folly," Barb said. "The labyrinth is Charlie's folly."

But they have a shared passion for other areas in their landscape, especially their front-yard iris garden, which is filled with more than 50 varieties. "They're our first love," said Barb. "They are so elegant, detailed and pretty."

The couple started planting flowers in their sunny front yard because its slope was too steep to mow. They focused on irises because Charlie's parents were iris collectors. Then they added other perennials, including lilies, phlox and black-eyed Susans so they'd have blooming color all summer long.

After the front yard was complete, Charlie started building patios in the front so they'd have places to enjoy the view. Then they turned their attention to their extra-deep back yard, where they removed buckthorn, and Charlie started building stone retaining walls and paths. The stonework — "the way it all works together" — is what he's proudest of in their garden, he said. "Who knew when I started it. I could just imagine it."

Over the years, they've gradually added a series of back-yard gardens, including a hosta garden, a rain garden and a rock garden, plus rustic and colorful garden art, including brightly painted wooden doors and old wooden extension ladders. "Charlie was in a store and saw them displaying wares from hanging ladders," Barb said. "He decided he had to try it here."

The Greens' front and back yards have very different personalities. While the front is sunny and a riot of blooming color, the back yard is more shaded and serene. "This is a much more calming place, surrounded by greenery and away from the street," Charlie said.

Their deep rear yard adjoins several others, which gives them the opportunity to experiment with the Japanese garden philosophy of "borrowed views."

"We were at the Japanese garden in Northfield," Barb said. "Japanese gardens use things in the distance as part of the vista." From the Greens' patio, they can see three other yards and a pond. "It's shared visual space — not ours to take care of, ours to look at and enjoy."

Open vista

One garden philosophy the Greens don't embrace is the concept of distinct garden "rooms." Their gardens, even the themed ones, like the knot garden and labyrinth, are integrated with and open to their other garden features.

"Lots of people like to do gardens with rooms, but I like seeing the whole vista," Barb said. "I can't see cutting it up."

Charlie concurs. "If you start putting up rooms, you lose the view," he said. "When I built the bower, I did it with a trellis that's open, so your eye can stop or go past."

Having adjoining gardens in back has helped them connect with their neighbors. "They're a block away if you go by the sidewalk, but the gardens are right next to each other," Barb said. "I didn't know them at all until I started gardening." Now they compost with their back-yard neighbors. "I built the bin, and our neighbors put stuff in it," Barb said. "Gardening is a shared experience."

Springtime is the Greens' favorite time to share their garden. In early June, when the irises are blooming, their front yard is a kaleidoscope of color and fragrance. It's too beautiful to keep to themselves, so about nine years ago, the Greens started hosting an annual spring garden party.

"The first year, we invited hard-core gardeners," Barb said. "Now it's grown to any friends — people from work, church and the neighborhood." Last year, 70 people showed up to stroll and chat — and bring home cuttings. "It's a successful garden party if people come and take plants," she said.

The couple's ambitious garden is a lot of work, especially for two busy people with day jobs — Charlie is a professional fundraiser; Barb is a pharmacist. But they've found ways to minimize the workload.

"We design things so we don't have to be on top of it every day," Charlie said. The garden is almost all perennials. "The only annuals are in pots," Barb said.

And they use a lot of mulch. "It keeps the water in, and the weeds down," Barb said.

Working in the garden, even after a long day on the job, is therapeutic, they've found. "A lot of cultures are tied to the land," Barb said. "Ours is not. We're a very mobile society. But the garden brings you back."

Kim Palmer • 612-673-4784