While you may envision a bonsai tree sitting on a windowsill in your home, most of the trees used in classic bonsai require life outdoors and the changing of the seasons in order to go through their dormant stages. For this reason, choose plants for bonsai that grow well in your area. Plants that work well for bonsai include pine, spruce and pomegranate trees.
Grow trees from seed. This can be a rewarding way to begin your bonsai hobby and you'll have the satisfaction of knowing you nurtured your creation from the beginning. However, be prepared to wait up to three years for your seed-grown trees to be big enough to begin the pruning and shaping process.
Choose your plant. In the beginning, it's safest to choose plants that are common and grow well in your area. If not growing your own seedlings, look for nursery stock first; these specimens are already accustomed to growing in containers. Another option is to check a nearby wooded area for young seedlings. Look for a well-rooted plant with good branches, attractive bark, and a trunk that is in proportion to the whole tree and gives the illusion of age.
Plant your seedling in a training pot. This is a nursery pot, 8 to 10 inches deep, with a large diameter and good drainage holes. Do not plant your tree directly into a small bonsai pot; it needs the training pot to adjust from a deep nursery container, ball and burlap, or landscape growing to the shallow confinement of its final pot. Plant your tree in a coarse, well-draining potting mixture. Leave the plant in the training pot until it develops a strong, fibrous root system and full foliage.
Complete all foliage work. Prune and wire once the tree is established. Do not transplant into a bonsai pot before this work is done or the process could dislodge your bonsai tree's newly placed roots.
Transplant your pruned and wired tree into a bonsai pot. Remove it from its transitional pot and comb out the roots, pruning those that are wiry or have grown stiff. Trim the fibrous roots to fit the bonsai pot and spread them out in the container. Turn the front of the pot to face you and plant your tree slightly off-center with the more heavily-branched side facing the center. This placement establishes the asymmetrical balance seen in the classical Japanese design. Cover the roots with coarse, porous potting soil.
Water your bonsai tree thoroughly and place in a dry, protected place for the next week. Check the soil moisture daily but do not water until the soil on top begins to feel dry.