Visiting the Plymouth gardens of Don Untiedt and Jim McKee is like unwinding after a hard day at work.

Before you reach the front door, you can hear the soothing sounds of a waterfall that cascades into a small pond. You can take a rest on the stone bench, or continue along a rose-lined path that leads to a decorative iron gate, which beckons to the hidden back yard. There, you’ll be treated to an English hybrid tea rose garden, Japanese woodland beds and three more waterfalls flowing down a hill to a sandy beach on Schmidt Lake.

“We call it ‘Der Serenity Garten Platz,’ ” said Untiedt, who is of German heritage. “It’s very peaceful walking down the hill with the water flowing.”

The garden is quite an accomplishment, considering that when they bought their home in 2004, the yard contained only the most basic ingredients: humdrum hosta and strips of scraggly wildflowers.

The men, for whom gardening is a shared passion, started making their mark in the front yard. “We wanted to greet visitors with a European-style garden with touches of Asian elements, using our proven Minnesota cold-tolerant plants,” said Untiedt.

They mingled rhododendrons, azaleas and pink hydrangeas with textural Japanese ferns and yews. For season-long color, they planted tulips and daffodils along the driveway and perennial beds packed with phlox, lupine and coneflowers. In the sunniest spots, they planted dozens of hardy shrub roses, including Sunrise Sunset.

A year into their garden, they were seduced by the hypnotic power of waterfalls, aquatic plants and darting koi they saw on a pond tour sponsored by the Minnesota Water Garden Society. They decided that their yard had to have a water feature, too.

McKee and Untiedt hired Josh Kiecker of Sculptured Earth in Delano to help them design and install a small waterfall and koi pond near their home’s front entrance. “For a small space, it’s very visually stimulating,” said Untiedt.

The front gardens were just a prelude to what they had planned for the expansive side and back yards.

To mark the entry to the yards, which aren’t visible from the front, the men installed an Old World iron gate designed by artisan Denny Sandin of Mill Pond in Montrose, Minn. It’s adorned with decorative roses, ferns and a heron.

“The gate reflects our interest in roses and wildlife,” said Untiedt, an interest that’s evolved from easy-care shrub roses to more tempermental hybrid teas.

Against conventional garden wisdom, the men planted hybrid tea roses on the north side of their garden. When those first few thrived, they added another 60 or so.

“The shape and size of the blossoms are so stately,” said Untiedt. The tender, high-maintenance roses have to be buried and covered every year before winter, but to him, they’re worth the effort. “I hate tipping the roses in the fall. But I love raising them in the spring.”

To give the side-yard garden an English country feel, they planted a backdrop of conifers and other shrubs and put in a brick walkway. And because they were so enamored of the water feature in the front yard, they replicated it in the back yard, but on a larger, showier scale.

The steeply sloped yard was ideal for multiple waterfalls, as well as a stream that flows into a large koi pond. Water iris and arrowwood emerge under the falls, which are carved into the hill.

To control erosion, they enlisted Ray Campbell of Campbell’s Signature Landscapes in Clearwater, Minn., to help design the multi-level stone steps and eight terraces, made of Minnesota fieldstone. A wooden footbridge spans the koi pond, which is ringed by hostas and ferns.

The best view of the waterfalls is from the bottom of the hill, while standing on the little beach.

“We’re always looking for ways to improve it. But I really like it the way it is,” said Untiedt with a laugh.

So do scores of garden lovers who have come to see this suburban Shangri-la during tours sponsored by the Minnesota Water Garden Society, the American Rose Society and the Men’s Garden Club of Minneapolis, to name a few.

On one tour, Untiedt watched a woman and her daughter closely inspect every garden bed. Finally, the woman approached Untiedt and said she’d “traveled all over the world and has never seen a rose garden as nice as this.”

Their garden, it seems, has lived up to its name.