Growing a bonsai tree successfully, indoors and outdoors
Q I bought a bonsai — a juniper — but it doesn’t go well in my apartment. What can I do?
A. Juniper is not a houseplant, and therein lies the problem, or at least a large part of it. Junipers are temperate climate plants and should be outdoors.
Yours is probably Juniperus procumbens, a low-growing shrub native to southern Japan and commonly sold as a bonsai due to its low-growing habit and gnarled appearance.
“Bonsai” roughly translates to “tree in a pot” in Japanese. In the West, the word is used to describe virtually any miniature container tree, whether authentically trained bonsai or simply small rooted cuttings. Technically, however, the term should be reserved for plants grown in shallow containers according to the exact principles of bonsai pruning and training, resulting in an artful miniature replica of a mature tree in the wild.
Many vendors in malls, grocery stores, and street fairs are cashing in on the bonsai fascination by selling young rooted juniper cuttings like the real deal, and claiming it’s good to grow them indoors.
“These plants are a curse for bonsai trees,” said Jerome Rocherolle, owner of Shanti Bithi Nursery in Stamford, Conn. “People buy them thinking they have an instant bonsai for their home, and within months the plants are dead, and the bonsai gets a bad rap.
Bonsai, he said, comes in two varieties: indoor and outdoor. This last type – mainly found in temperate regions, in the northern hemisphere – includes pine, cedar, ginkgo, Japanese maple, hornbeam and juniper. These plants thrive on sun, fresh air, and moisture. Many need a cool dormant period, and if they are deciduous, like the Japanese maple, they will lose their leaves in winter.
A hardy outdoor bonsai like the juniper needs to be overwintered in several ways. Some bonsai masters place theirs in a greenhouse or conservatory that doesn’t get hotter than about 55 degrees; others use a sunny garage or outdoor cold frames. And some bury the largest specimens in the ground, up to the edge of the pot, and cover them with mulch.
But none of these options will work for you if you are a beginner or live in an apartment.
Indoor bonsai – tropical and subtropical plants like ficus, Ming aralia, podocarpus and dwarf jade – are easier to care for and will thrive indoors. They require much the same treatment as regular houseplants, with one exception: they usually need to be watered more often, as they live in shallow pots without much soil.
To fully experience the art of bonsai, you must prune, train, wire and root your plant as it matures. Information on how to do this can be found on the Shanti Bithi Nursery websites (shantibithi.com), the Bonsai Clubs International (bonsai-bci.com) and the American Bonsai Society (absbonsai.org).
But be careful. As with many types of advanced horticulture, it’s hard to leave the precise world of the bonsai hobbyist once you’ve entered it.