A wisteria and Japanese maple share space with a sailboat along the docks below Eastlake Avenue East. Despite being exposed to the weather and stuck in pots, plants have grown enough by midsummer to conceal their containers as well as the edges of docks and houseboats.

Determined to have an entire garden rather than merely a few pots of flowers on her front porch, garden artist Nancy Hammer grows roses, shrubs and perennials on her little slip along Wandesfordes Dock. By midsummer, her roses are in their second flush of bloom and the perennials have grown tall. "I love hot colors," says Hammer." I always have red and orange out there." The exotic scent of lilies, blooming in shades of golden orange and lavender, mixes with the sweeter, softer perfume of the English rose 'Abraham Darby.'

Plantings extend the length of the docks; here wooly wands of verbascum tower above diascia, calla lilies, artemisia and Verbena bonariensis.

Foliage plants such as purple and yellow hebes (H. x franciscana 'Variegata') and silvery-leafed Senecio greyi appear in pots on both sides of the porch to anchor the more changeable perennial and bulb plantings. These include daylilies, euphorbias for a splash of early season chartreuse, drumstick alliums, hardy geraniums and plenty of silver-gray artemisia to cool it all down. Bronze-colored phormiums and ornamental grasses add dark notes as well as vertical line, and Hammer recently added a couple of small palms for spiky contrast. Houseplants join the mix to summer out of doors.

Hammer has found that single-season plants will fare just fine in much less soil, so annuals like marigolds, zinnias and geraniums are planted in pots whose bottom halves are filled with styrofoam noodles. This cuts down on the weight of the pots and plantings, an important consideration in keeping the houseboat from tipping. "It really reacts to weight, and it doesn't take much to tip it enough so that you roll out of bed wrong, or the refrigerator doesn't close tightly," says Hammer. This year, she used smaller pots, although just as thickly and variously planted as ever. "It is bad feng shui if everything grows too big and blocks the entry," Hammer explains.

Garden artist Nancy Hammer has made an entire garden on her diminutive front porch alongside the Wandesfordes Dock, where she grows roses, annuals, perennials and bulbs in an assortment of pots.

She waters all the pots daily and fertilizes often, as plants are crowded in terra-cotta pots, baskets and even black plastic pots, concealed by overflowing foliage. "One year I had ducks nesting in my pots up until June, so I couldn't plant until late," Hammer says, laughing about one of the unique challenges of waterside gardening. "So now I leave plants in over the winter and see what survives."

Bob Lilly, gardening for nine different houseboats lining a dock just a few blocks south, takes full advantage of gardening waterside. The unobstructed light, further enhanced by reflections off the water, makes sun-lovers like helichrysum, abutilons, lavender, rosemary and brugmansias grow large and hearty. If the raccoons don't get the tomatoes, they ripen early in all the light and warmth. The up-close expanse of lake water moderates winter temperatures, so many tender plants happily winter over here. Lilly complains he's had much less room to play around with annuals after the last couple of mild winters because so many plants, even with the confined root-runs afforded by containers, have survived and grown large in the encouraging weather.

Left: Unobstructed sunshine reflects off the lake, creating conditions so unusually warm and bright that a lemon tree lavishly produces fruit in its pot up against a yellow houseboat. Right: The wide spotted leaves of a hybrid calla lily (Zantedeschia) add lushness to the mixed container plantings. Strong colors, like the calla's hot orange flowers, look their best in the bright, sunny conditions on the exposed docks.

Lilly uses mostly wooden containers because they weigh less than the terra-cotta pots he prefers, but he doesn't shy away from growing large plants, including fruit trees. His own houseboat is shaded by a Japanese hemlock that has grown in the same pot for 25 years. The evergreen tree is festooned with the yellow bells of a huge abutilon that grows up and over its branches. The hemlock, along with a couple of rhododendrons, a bristle cone pine, lavenders, rosemary and evergreen ferns, carries the display through the winter months.

Dozens of statuesque lilies are underplanted with froths of ferny corydalis. Buddleias attract butterflies. Tall wands of wooly verbascums, staples of British flower borders, are a surprise to see growing in waterside pots. A community lemon tree flourishes grown up against a bright yellow houseboat. Because the heavy winds beat up the plants, Lilly tries to confine his gardening to the houseboats' north and east sides, but plants spill over onto any available surface. Sedums, echeverias (which Lilly takes indoors in winter) and lewisias love the windy exposure. The dark-leafed, dark-flowered Dahlia 'Bednall Beauty' loves the unobstructed sunlight. Encouraged by the warmth, lemon verbena grows big and branched, fragrant and shiny. Abutilon 'Souvenir de Bonn,' with maple-like leaves trimmed in cream and orange bell-shaped flowers, is usually an annual in our climate, but here it has wintered over to grow large and robust.

Bob Lilly, dockside gardener extraordinaire, squeezes in a birdhouse amid the bamboo that grows in pots outside his houseboat. Songbirds are encouraged, but raccoons and geese can be destructive to these floating gardens, and ducks like to nest in the pots over the winter.

A plant collector, Lilly grows unusual plants, many of which he has brought back from England. He mixes them in with the more familiar clematis, honeysuckle and calla lilies that make up the summer dockside lushness. Quite literally, Lilly's work shows the results of thinking outside of the box. "I try everything," says Lilly, "there are no limits to gardening in pots, except for plants getting too big or heavy." Lilly grows a startlingly beautiful crocosmia ('Seven Sunrise') in brilliant shades of watermelon, orange and yellow, and a bicolored flowering tobacco, plus hardy geraniums and persicariasthat likely won't be available for awhile even in the best nurseries.

Lilly pulls up buckets of water from the lake to water the hundreds of containers he cares for, spending several hours every day to keep them from drying out on the warm and windy docks. He feeds each plant once a week with Rapid-Gro, and uses a lightweight potting soil, mixing in fresh, rich soil each spring to renew its texture and fertility. Plants blowing over in the wind is the worst problem, and many of the taller plants are anchored to the decking. Lilly manages to laugh about the geese who pull out his plant labels, and nibble nearly everything. Last summer, the geese kept the mimulas nicely pinched back. Leggy annuals aren't a problem with a goose patrol on the job.

Perhaps it is the diminutive size of most of the houseboats or the expanse of smooth water that reflects the plants, but the impact of these floating gardens is disproportionate to their size. Maybe what impresses most is the sheer courage of the gardeners who undertake to grow entire gardens in pots, never mind the exposed conditions. Lilly's audacity in growing more species in pots than most people can fit into a suburban backyard should be encouragement enough for container gardeners to move beyond tidy pots of petunias or hanging baskets of geraniums. Hammer and Lilly, along with other houseboat gardeners, have created flowery garden communities with a bit of clay, soil, water and a large dose of inventiveness.

Valerie Easton is a horticultural librarian and writes about plants and gardens for Pacific Northwest magazine. Her e-mail address is vjeaston@aol.com. Mike Siegel is a Seattle Times photographer.