The bonsai tree is just like any other tree, except that it is pruned and shaped into miniature form. With diligent care, these trees can provide many years of enjoyment and beauty. Potting the bonsai is the first step to the bonsai tree's healthy lifespan.
Choose a potting container that meets the needs of the bonsai. Consider not only the current size of the tree, but its intended size. The container should meet the tree's height, width and trunk diameter. Taller bonsai trees with less width should be planted in containers that have a length that is approximately two-thirds the height of the tree. Shorter bonsai trees with wider branch spans require pots that are slightly larger than two-thirds the width.
Fill the container with nutrient-rich soil. Bonsai trees require plentiful nutrients and prefer a sandy loam. Mix the soil with one-third sand to promote this environment. A common mix used by avid bonsai growers includes one-third soil, one-third peat compost, and one-third sand. Both combinations promote a well-drained and loose environment for the root system.
Line the bottom of the container with a well-mixed layer of soil. Place the bonsai tree on the layer. Adjust the root system so that it lies comfortably. Fill the container with the remaining soil. Pack loosely to provide good aeration.
Pot the bonsai quickly once it has been removed from its original container. Bonsai tree roots dry fairly quickly and cannot tolerate drought periods. Dry roots can cause tree damage and potential death.
Water the bonsai immediately after planting. Use a light watering, just enough to take the tree through the rest of the day. Water the bonsai the following day, only after checking its moisture levels. Place your finger about an inch into the soil around the root system. If the soil feels dry, water the bonsai. Develop a good watering schedule that provides ample irrigation without overwatering. Overwatering will cause wilting, yellowing and potentially disease susceptibility.
Fertilize the bonsai with a well-balanced fertilizer using half-strength. The fertilizer should contain a combination of phosphorous, nitrogen and potassium. Avoid fertilizing the bonsai immediately after potting. Wait at least three weeks for the first fertilizing. Never fertilize a dry or sick bonsai tree.