They say that you can take the measure of a man - or a woman, for that matter - by his garden. We all know the frenetic character whose garden is crammed with statuary, trellises, and topiary. Or the laid-back person whose beds harbor only a swath of juniper and a row of hostas. Some gardens scream, "Look at me," just as some people do. The shy or solitary may choose to create a garden unseen by anyone save intimates.

Retired school superintendent Arthur Pierce's garden in the historic district of Belfast speaks volumes about its creator. A life-long educator with an unquenchable enthusiasm for new projects, he has over the last decade transformed a featureless lawn on a postage-stamp-sized lot into a surprisingly varied and harmonious garden. Just as the best teachers never stop being students of the world around them, Pierce has been absorbing knowledge and materials from the world around him, continually experimenting and seeking novel solutions for his plants' display.

Yet the garden is modest, a space that doesn't trumpet its beauties and seemingly exists only to give pleasure to its creator and his closest neighbors. Some of its most interesting features, like the bog he created in a shady corner, are virtually hidden to passersby, though one might spot the towering iris and long-flowering astilbe that flourish in the bog's wet conditions. Similarly, Pierce is disarmingly modest about his quite real accomplishments, as the best students often are. "Oh, almost anyone knows more about gardening than I," he says. His wife, Deborah, adds a dose of reality: "He pretends he doesn't work hard at it, but he does," she confides. When he's approached about his garden, he usually points visitors to his neighbors' more showy efforts. He's a genuinely self-effacing guy. If you weren't aware of his other passions - mountain climbing and canoeing - you might never find out about them either.

His hard work and ingenuity have combined to make a garden that causes drivers to slow down as they pass, especially in springtime when his yard provides one of Belfast's first glimpses of long-awaited color. Multicolored crocus show their faces first, followed by swaths of tiny blue iris reticulata and drifts of sunny yellow daffodils, large and small. Warmed by the southern exposure, the eye-catching beds are a carpet of early bloom. As spring gains momentum, a symphony of iris - white, blue, yellow, purple - is punctuated by notes of tall purple lupine. Later in the season, red and white daylilies and Asiatic lilies, clematis vined on trellises, and roses like the bubble-gum pink "Morden Centennial" and sheer white damask "Madame Hardy," take up the melody.

A man who looks younger than his seventy-nine years and with the ruddy complexion of one who delights in the out-of-doors, Pierce built all the stone work in his garden after taking a one-morning workshop with Carleton E. Jones, master wall builder at Fieldstone Gardens, Inc., of Vassalboro. A handsome retaining wall came first, complete with steps, followed by two three-by-five-foot ponds (now filled with water lilies and papyrus), a couple of benches, and a small bridge made from a single slab of granite. In the best Yankee tradition of making do with what's available, much of the stone was either salvaged or surplus. "The first half of the retaining wall came from a Belfast blueberry farm," he explains, while the other half, the benches, and the bridge were surplus curbstone and discards acquired through a local firm, State Sand and Gravel. The granite steps were salvaged from the base of an old neighborhood fence that rotted and wasn't replaced. "My wife and I transported each step by wheelbarrow for a block and a half!" he says. Plants were salvaged as well, most notably centenarian irises rescued from his late mother-in-law's garden in Limington, along with her pink peonies. An unusual brown bearded iris, "Root Beer," was provided by the librarian at the Belfast Area High School; hostas came from a retired UPS driver in Swanville. When Pierce was starting out, numerous plants were passed on by his neighbor, noted plantswoman Muriel Krakar. A line of arborvitae at the rear of the house was a bargain at "only eighty dollars for all of them."

Pierce has found clever solutions for transforming his lot's natural defects into assets. The retaining wall was built along a drop-off left where soil excavated for the house's foundation was piled. On the other side of his house, a round, raised hosta bed built of stone sits on top of the spot where matted roots and the traces of a previous owner's RV made the soil unsuitable for growing. A bubbling fountain in the center was created from an upturned terra-cotta pot. Some of the garden's most interesting features are tucked away, like the bright yellow experimental azalea, "Fruity Lemon," hidden behind the house, and the wonderfully fragrant, double blossom blue "President Grevy" lilac close by it. But nowhere is his problem-solving ability better seen than in the bog he created seven years ago.

In its former life, the bog was a burn pile in a low, shady corner near Pierce's back fence. Previous owners may have disposed of trash and boat scrapings there; the soil was contaminated with lead. He laboriously scooped it all out, rolled out a rubber liner and punched drainage holes, then filled it with rich soil. What had been a spot that said little is now home to the longest blooming astilbe in the neighborhood, plus Jack-in-the-pulpits, extremely tall Siberian irises, marsh marigolds, ferns, and hostas, all of which love the cool, wet conditions. Eleven dime-store goldfish - they winter over in a tank in his basement - are charged with keeping mosquitoes in the pond at bay, and "apparently they are up to the challenge," he says, since insects are not a problem. It is one of the most interesting features of the garden, but unless you had been told it was there, you wouldn't know about its unique character. As Muriel Krakar puts it, "Who else around here has a man-made bog?"

pierce's thirst for new challenges led him to another project that would be the envy of someone half his age. The way he explains it, the idea came to him a few years before his 1997 retirement as superintendent of schools in Belfast, following superintendencies in Brewer, Bangor, and Burbank, California. He read that Maine's former senator, George Mitchell, had celebrated a sixtieth birthday by climbing Mount Katahdin. "I thought, well, if he can do it, maybe I could too," Pierce says. Although he had done some hiking while an undergraduate at Dartmouth and had always done "outdoors kinds of things," he had never particularly pursued mountain climbing as an activity.

Stand aside, George. Katahdin became for Pierce merely the first peak achieved of The Hundred Highest, the sixty-seven peaks 4,000 feet and above in Maine, New Hampshire, and Vermont, and the other thirty-three "shorties" below 4,000 feet. Over the past ten years he has climbed all of them, mostly alone. "My wife has done a few with me, and my three adult children have each had a turn. Some of the peaks are bushwhacks, meaning there's no trail. In that case, I usually take someone with me, so if one turns an ankle, one has . . . someone to talk to," he laughs. Having conquered New England's peaks, he then turned an eye southward to North Carolina and Tennessee, "because that's the only place on the East Coast where there are 6,000-footers." He's already climbed thirty of the forty, following trips there over the last few years. His next challenge? The Adirondacks.

When he's not climbing, he's canoeing. "Each year I do a different Maine river, from as near the source as I can conveniently be, to the ocean or the Canadian border, whichever the case may be," he says. He canoes them in sections, sometimes accompanied by his wife, Deborah, or his son. He's now done all the major rivers, including a wild roller coaster of a ride down the St. John in flood condition - "in three days when it normally takes five to seven days."

Pierce and his wife spend their winters in their Carrabassett Valley house, where they both ski "every day that it's possible to ski," which can mean over a hundred days a season. He also maintains a section of the Appalachian Trail there, making sure no inappropriate encroachment or trails have been built. Summers are spent in a cottage on the Isle of Springs, a small island in the Sheepscot River near Boothbay, that his wife's Maine ancestors, the Libbys, helped settle.

The breadth of his activities can be seen in the large relief maps that line the walls of his house. Different colored push pins indicate mountains already scaled and those still to be climbed, places he's camped, points that he put in and came out of rivers, sections portaged, trails maintained. It is a multicolored whirl recording the work of a man who continues to be both a student and a teacher, still seeking new challenges and measurable achievements.

Did he plan his retirement this way? He shakes his head. "No, I just did lots of things I wanted to do." He pauses. "I'm dedicated to having fun. And Maine is a good place to be to have fun."