Phoenix has a year-round growing season appropriate for a wide variety of plants if enough water and fertilizer are available. True bonsai trees are standard-sized trees that have been stunted by root pruning and adverse growing conditions. They are not dwarf trees that have been bred to be smaller. While any tree can be trained as a bonsai, some are more adaptable in Phoenix than others. Some bushes are grown in Phoenix to look like bonsai trees. Lantana is one example.
Bonsai are trained to look old and weathered by wrapping the branches with wire and bending them gently over time to be up-swept or down-swept. The trees have thick, gnarled trunks, sometimes grown at an angle. In Phoenix, start with a plant that has the thickest trunk possible, advises the Phoenix Bonsai Society.
Desert trees such as palo verde and ironwood grow up to 30 feet tall and wide. They have small leaves as do most native vegetation. Small leaves make better bonsai because the tree in miniature form looks more realistic. Large-leaved trees look odd when the leaves are 6 inches wide on a tree that's only 18 inches high for example. Besides palo verde and ironwood, other plants appropriate in Phoenix for bonsai include bougainvillea, Mexican ebony and weeping fig.
Bonsai Care in Phoenix
Use a course potting mixture with up to 75 percent inorganic material such as crushed quarter-inch decomposed granite and 25 percent potting mix. Water more frequently since the climate is dry. Repot less frequently. Use a slightly deeper and wider pot than traditionally used to insulate the roots.
Trees that require a cold dormancy period are difficult for Phoenix because the climate is warm in the winter. A tree genetically programmed to go dormant during the winter must go dormant or it won't survive. Junipers, often grown as bonsai elsewhere, don't do as well in Phoenix because of the heat. They are outdoor plants and should only be brought inside for display.
Bonsai are kept stunted through a limited watering program and a shallow root system in a shallow tray. During the hot summer months and even the cooler months of April, May, September and October, shallow trays dry out very quickly and put the bonsai at risk of wilting.
Since bonsai are small they are easy to move around. Keep the bonsai in the most ideal location throughout the seasons. Move it to where it receives morning sun and afternoon shade in the summer and back out into full sun during the winter.