One doesn’t expect to see a tropical jungle growing on the streets of historic downtown Annapolis. But if you bypass the traditional tourist destinations and make a detour down Cathedral Street, that is just what you will find. Here, enhancing a modest, two-story apartment house, is a favorite local attraction - the wildly exuberant garden of Nancy Lowry Moitrier and her husband, Pierre Moitrier. Having no place but a porch, one planter box, and the sidewalk to make a garden, the Moitriers grow nearly all their plants in pots.

Although Nancy was hampered by living where there was virtually no earth to till, her desire to garden was sure to find expression. And did it ever.

The garden started humbly enough with three pots, filled with the leftovers (a flat of pansies and a bag of chicken manure) from a trade show display, that Nancy placed on the porch steps. As the season progressed, friends brought new treasures, and soon another cluster of pots was needed to contain them all. She then tucked flowering plants between the billowing boxwoods and hollies that filled the building’s street-side planter box.

The next step was to petition the other five tenants in the apartment house for their consent to let her make a garden room of the front porch. “Everybody was very agreeable,” recalls Nancy. “They all added their different plants to the porch.” When a new electrical system resulted in an unattractive line of outdoor meters, Nancy started adding pots to the Dean Street side of the building. Super-sized pots were then added along the front, while repairs to the porch brought further planting opportunities.

The last large addition to the garden came during the winter of 2001 when Nancy and Pierre were married. At the wedding, potted plant decorations were, of course, de rigueur, and the Moitriers returned home with another dozen pots to take care of. Today, the garden consists of about seventy containers.

While a flat of simple pansies may have inspired Nancy’s original container pots, she now grows a remarkable selection of the newest and most unusual plants available. (The fact that the couple’s cats are called Saruma and Indigofera - the botanical names of two fairly uncommon genera - provides a clue as to the scope of plants with which they are familiar.) In her pots, she mixes annuals (including the latest varieties of petunias and zinnias) with an ever-growing palette of tender perennials. Magnificent tropicals - such as the towering banana in the corner tub, splashy cannas and coleus, peachy abutilons, and the chocolate-leafed Euphorbia cotinifolia - make powerful summertime statements. Vines clamber up the porch railings and drape across tuteurs. There are even conifers for winter interest (as well as summer texture) and hardy perennials such as the paddle-leafed Bergenia cordifolia, whose precocious, hot-pink blossoms provide color before many summer-bloomers venture their first set of leaves.

Because the Moitriers grow so many tender and tropical species, the over-wintering of cherished specimens presents a serious challenge. When the nights get chilly, Nancy and Pierre start hauling as many plants as they can up to their second-floor apartment. Most of the pots left outside are placed in a sheltered corner, squeezed close together, and blanketed with mulch and a microfiber fabric to protect them from the cold. These efforts yield mixed results. Inside they have to deal with occasional outbreaks of mealybug and whitefly - even, Nancy relates, when beneficial bugs come to the rescue. “Last year we had praying mantises hatch inside the house. I thought, this is great; we have the whole integrated pest management system going on here. And look how cute they are. Look, there’s one on the glass; there’s one on the coffee cup. Unfortunately, they didn’t live long enough to do a good job.” And in spite of the joint effort, some of the plants they tried to save that year died. Looking on the bright side, as Nancy will tell you, the death of one plant does provide an opportunity to try another.

The Moitriers’ approach to planning their garden is experimental. And Nancy packs a lot of plants into a pot. Nevertheless, her combinations show an uncanny ability to put untried plants together to splendid effect. A red-stemmed Swiss chard potted with a burgundy-centered, clover-like oxalis; a green cherry tomato vine used as a trailing chartreuse accent in a hayrack of silver foliage and purple flowers - the combinations are shocking and delightful.

However, disappointments do occur. The summer may be cooler or wetter than predicted, plants grow too fast or too slow, some seem not to want to grow at all. This year Nancy struggled with “the leaning tower of eucalyptus,” a young tree that was growing so vigorously it had to be chained to a post. “But what’s neat about container gardening is that you can move things around,” she says. “If a plant gets bigger than I thought it would, I’ll put it to the back. I actually think it’s a great way to learn about putting plants together, especially using annuals because they grow so quickly you soon see what works and what doesn’t.”

Gardening is simply in Nancy’s blood. Her parents work in the nursery business and her grandmother wrote the visionary Floral Art for America (1964). Nancy holds a degree in horticulture from Penn State University and once worked at the National Arboretum in Washington, D.C. She met Pierre during a trip abroad to study English garden designs.

Much of what Nancy has learned over the years she applies to the couple’s business, Designs for Greener Gardens. And although Pierre has gained most of his gardening experience since moving to the United States from his native France, he has proven to be an extremely quick learner. With a degree in “countryside management” (finding ways to preserve and reinvigorate economically threatened rural communities), he contributes a good measure of practicality to their work. Their business provides a variety of services such as garden consultation, in-ground and container garden design, installation, and maintenance. Annapolis Pottery on State Circle was one of their first clients, and in Annapolis alone they now serve more than twenty-five container gardening customers, including the restaurant Tsunami. Getting owners to take adequate “after care” of their containers has turned out to be the trickiest part of their job. Plants in pots need lots of water. And on hot summer evenings, it’s not unusual to see the Moitriers making emergency runs to their clients’ gardens, laden with gallon jugs of water, in an attempt to rescue the wilting plants they’ve passed on their way home.

Plant lovers can be sensitive to the criticism that their passion has made them obsessed, immoderate, or just plain out of control. Nancy used to tease her own father for growing far too many plants. Now he teases her. But given the daily compliments from passers-by who say how much they enjoy the garden, the Moitriers have no reason to apologize for the abundance of their display. On the contrary, they should feel encouraged to do more.

Catherine Umphrey is an Annapolis-based freelance writer and owner of a garden design business, Felicity Green.