But "lazy person's bonsai" might be a better description, because it's far easier and less of a commitment, and you can find everything you need to make them at any home and garden store.
"Kokedama takes off from the bonsai concept," says Kanako Yamada, who makes them at her business, Kodama Forest, in San Diego. "The difference is, bonsai is usually for outdoors — they are brought in when a guest comes, but regularly they will be outside." Kokedama, by contrast, were made to be enjoyed indoors all the time.
Westernized kokedama (which means "moss balls") give this concept a few twists. One is that instead of just displaying them on pretty dishes, we're hanging them up; the other is that we're taking them outdoors as well.
The basics couldn't be simpler: Put a plant in a ball of soil, wrap it in moss and tie string around it. In Japan, kokedama are made with bonsai soil, but that's not necessary or even a good idea in some climates. "I have tried it and it works fine, but I didn't see a big difference, so I don't bother spending the money," says Lauren Hill, senior gardener at Longwood Gardens in Kennett Square, Pennsylvania.
She uses about two-thirds potting soil and one-third another kind of soil with more clay as a binding element, then adds water and adjusts the mix as necessary. "You want to mix till you get the consistency of a meatball," she says.
In Southern California, Yamada says that bonsai soil or any soil with too much clay will dry out too much, so she simply uses the soil the plant is potted in, adding peat moss if necessary.
Another difference from the Japanese style is that instead of live moss, dried sheet moss is used, which you can buy packaged at craft and garden stores. Soak it in water and you get a green-brown sheet you can wrap. (Don't confuse this with sphagnum moss, which is silvery-grey and stringy and falls apart.)
The string that secures the moss around the ball can either be purely functional or part of your design.
"I use regular twine, but I've seen it done with rubber bands, colored wire, basically anything you can wrap around the ball," says Hill. "You can a wrap a bunch of times so you can see it and add colour, or just enough to hold it in place."
Kokedama should be hung in a way that's easy to take it down for watering, because you'll need to soak the whole ball. Hill soaks them for 15 minutes or so and then lets them sit till they're not dripping.
Outdoors, kokedama shouldn't be in direct sun where they will dry out, and if you live in a cold climate they'll need to come indoors for the winter. So choose plants with those factors in mind.
"We go for hardy plants that are tried and true, that in the summer can handle being outdoors, then can come indoors and handle low light conditions," says Chad Washburn of the Naples Botanical Garden in Florida.
He recommends plants such as philodendron, pothos, anthurium and miniature orchids, and says, "One of my favourites is parlour palms. You can buy quite small ones, relatively inexpensively, and they'll stay small in this setting. They do beautifully indoors and out."
Plants that don't rely as much on getting moisture from the soil are particularly easy. "Anything with that epiphytic growing style — things that naturally grow attached to bark and trees — those kinds of plants tolerate it really well because they naturally absorb moisture from the air," says Hill.
Like any container plant, your kokedama will eventually need repotting. Yamada says you can cut off the moss, prune the roots and put new moss on, the same technique used in bonsai to keep the trees small. But, she says, after a few years she usually likes to move the plant to a pot and let it spread.
Hill says that for many people, kokedama may not be a long-term way to grow plants in any case. "I think most people get impatient with how much watering they require, but for like a summer, or six months to a year, they're super fun to have around the house."
Still, kokedama provide some of the pleasures that Yamada learned about from her uncle, a bonsai artist in Japan who inspired her.
"He said, in a small pot he can make a small forest, and make people have a peaceful mind, a tranquil feeling," she says. "I wanted to pass that on to people."