Bitterroot Restoration

The art of bonsai began in China over two thousand years ago. A bonsai plant is not naturally small. It is done by growing the tree in a small pot or tray. It is kept small by shaping and root pruning.

It can be created from nearly any perennial woody-stemmed tree or shrub species which produces true branches and remains small through pot confinement with crown and root pruning. However, Bonsai is a collection of techniques to grow, train and care for a tree in order to shape it into a miniature but naturally and old looking tree and a poorly-tended bonsai will not be healthy and might die.

Most bonsai species are outdoor trees and shrubs by nature and they require temperature, humidity and sunlight conditions approximating their native climate year round. The skill of the gardener can help plants from outside the local hardiness zone to survive and even thrive, but doing so takes careful watering, shielding of selected bonsai from excessive sunlight or wind, and possibly protection from winter conditions (e.g., through the use of cold boxes or winter greenhouses).

Common bonsai species (particularly those from the Japanese tradition) are temperate climate trees from hardiness zones 7 to 9, and require moderate temperatures, moderate humidity, and full sun in summer with a dormancy period in winter that may need be near freezing. They do not thrive indoors, where the light is generally too dim, and humidity often too low, for them to grow properly. Only in the dormant period can they safely be brought indoors, and even then the plants require cold temperatures and lighting that approximates the number of hours the sun is visible. Raising the temperature or providing more hours of light than available from natural daylight can cause the bonsai to break dormancy, which often weakens or kills it.

Tropical and Mediterranean species typically require consistent temperatures close to room temperature, and with correct lighting and humidity many species can be kept indoors all year. Those from cooler climates may benefit from a winter dormancy period, but temperatures need not be dropped as far as for the temperate climate plants and a north-facing windowsill or open window may provide the right conditions for a few winter months.

Deciduous bonsai trees annually shed their leaves in winter as they enter their winter dormancy period. Deciduous bonsai include Maple, Larch, Crabapple, Apricot, Hornbeam, Gingo, and many Elm species, to name a few. Deciduous bonsai are not suitable for growing indoors during the winter months because they require their winter rest period, which is facilitated by the colder weather. Deciduous bonsai are known for their Spring and Fall foliage color changes. Colors typically range from yellow to oranges to deep reds.

Evergreen bonsai trees maintain their foliage throughout the season changes. Evergreen bonsai types include Junipers, Boxwoods, most Pines, and Azalea, to name a few. Some evergreen bonsai exhibit a dull green or yellowish tint to their foliage during their winter dormancy period. Most evergreen bonsai require a winter dormancy period, or rest period, in order to maintain their ongoing health.