Vashon artist Clare Dohna's mosaics for the garden, such as this cluster of spheres, are all a bit oversized, brilliantly colored and frost-proof.

Functional items such as arbors, pathways and benches are vehicles for imaginative decoration. Along with gentle breezes and dappled sunlight, however, come freezing temperatures, ice and relentless rain. Garden art, whether whimsical, elaborate or integral to the garden's structure, must be sufficiently sturdy to stand up to nature's ferocities.

Local garden artists have stepped up to the challenge, creating one-of-a-kind pieces meant to live outdoors year-round. Clare Dohna first realized the potential of mosaics when a big pottery piece she'd spent months working on in college blew up in the kiln. She glued the pieces back together, and liked the look.

The fragility of glass is married to the strength of steel in the goddess welded by Olympia artist Kim Merriman. Placed where the sun can shine through the colored glass, the pieces change as the sun moves through the sky.

After spending 20 years crafting and selling ceramic pins at the Pike Place Market, she was coaxed into mosaics when Sylvia Matlock, owner of DIG Nursery on Vashon Island, invited Dohna to participate in DIG's annual birdbath show. Dohna crafted a mosaic birdbath she liked so much that she kept it, making another for the show and becoming addicted to putting together the fired-ceramic pieces she makes herself. She rolls out slabs of clay, cuts out the mosaic pieces, fires them, applies a glaze for color, then fires again at hot enough temperatures to ensure they are frost-proof.

It is intricate, time-consuming work to make the tiny, bright bits and then fix them to a ceramic or concrete base to form birdhouses and birdbaths as well as oversize spheres, eggs and teacups. Dohna makes the raw materials for her mosaics, rather than breaking up found objects, hence the range of vibrant shades that define her work.

"I love all the colors, and to see how they go together," she says of her signature Caribbean and delphinium blues, and the silky plum, cranberry, turquoise and kiwi green that have such affinity with garden foliage and flowers. Dohna's pieces are slightly oversized, giving a mythic feel and a jolt of surprise to the garden. She laughingly explains that the wild colors and weird shapes in Dr. Seuss's books were a big influence on her work. Dohna's art is on view and for sale (from $300 to $650) at DIG Floral and Garden, 19028 Vashon Highway S.W., Vashon Island; 206-463-5096.

Kim Merriman's metal-sculpting career was born out of a welding class she took to make privacy screens for her own garden. From her first class, she fell in love with the equipment, smells and sounds of welding — unfamiliar to someone with a photography background who was working as a governmental-relations expert for Evergreen Community College. Merriman quickly realized the potential of combining the strength of steel and copper pipe with the fragility of glass, and because she is a gardener, wanted to take this juxtaposition of industrial and fragile outside. For some time, Merriman had been sketching curvaceous goddesses with wild hair, so when she bought her own welding equipment a couple of years ago, goddesses with unique faces, names and hairdos became her first projects. Now she does mostly site- or client-specific work, making architectural pieces for particular locations, and goddesses to suit a name chosen by a client.

Sunshine illuminates the colored-glass beads around the goddesses' necks or the curve of glass in their hips. Birds perch on the sprigs of their spiky hair, and no two are ever alike. Merriman also crafts huge dragonflies, rusty herons and birdbaths whose steel petals unfold to cup a pottery bowl. Her pieces cost from $200 to $600, and can be viewed or ordered at www.gardengoddessart.com. Both Dohna's and Merriman's art will be on display in booths and gardens at the Northwest Flower & Garden Show Feb. 19-23 at the Washington State Convention & Trade Center.