Ikebana is one of Japan's most popular traditional arts. Where once these flower arrangements were found only in private homes, now they're everywhere - in train stations, banquet halls and hotel lobbies.

Midori Tanimune practices Sogetsu ikebana, the newest and most abstract and avant-garde form, which allows the use of metals, plastics, and all sorts of sculptural or unnatural materials.

"I like to challenge limits," she says.

In a piece called "A Future Dream," Tanimune used a refrigerator shelf as a frame on which she hung clear plastic tubes. Inside those, she put tiny orange and green tubes filled with water and zinnias from her garden.

Another arrangement, called "Unlimited Boundary," comprised two windmills on the floor, a wave of black mesh, and an exotic melange of banana leaves, bird of paradise and anthurium.

"Very contemporary," she says.

Traditional is hard enough, though Tanimune makes it look easy. Here are some thoughts gleaned from several hours of class and interviews with her:

Besides the plants she brought to class, Tanimune likes to design with camellias, eucalyptus, flowering quince or cherry, freesia, Scotch broom, weeping willow, variegated aucuba, dogwood, iris (a classic), and even rose petals, which can be scattered about.

Choose plants in any season and remember: A bare branch can be far more evocative than one loaded with blooms. Your materials should be as they are in nature, whether nascent, in full bloom or aging. Each is beautiful and seasonal in its own way.

When designing, look hard at your material and ask yourself, "What do I want to speak?" Let it be with one voice, and then don't be afraid to trim, "give a haircut," or do surgery. "Sometimes, I take out. Sometimes, I put in," says Tanimune, who often twists flowers so they're "looking up to heaven," rather than facing down, or turned inward rather than out.

Some flowers, like the glamorous oncidium orchid, have a special character already. Leave them whole.

Three stems, different heights, always pretty.

Let each flower breathe. Space is key to ikebana design.

And consider your design a party. "When you have a party and somebody is speaking, somebody has to listen," Tanimune says. "We have to step back and let them speak. After that, everybody can play."

- Virginia A. Smith