The ficus bonsai is a slow to moderate growing tree that is intolerant to cold and drafty conditions. This tender tree thrives in moderate temperatures above 65 degrees F and will easily suffer damage when temperatures drop below 60 degrees F. The characteristics of the ficus bonsai require its indoor cultivation. However, the ficus bonsai does benefit from short outdoor periods for fresh air and sunlight.
Keep the ficus bonsai in a well-drained container that has several drainage openings at the bottom to allow the even exit of water.
Repot the ficus bonsai tree every two years. Remove the ficus from the potting container. Gently remove the excess soil from the root system. Inspect the root system for signs of dead, damaged or wilted roots. Remove with sterile pruning shears any damaged roots. Never remove more than 1/3 of the root system.
Repot the ficus in a container that is slightly larger than the root system. Mix equal amounts of nutrient-rich soil and organic compost. Line the bottom of the potting container with a layer of soil so that the container is about one-third full. Position the ficus bonsai in the center of the pot. Fill the container with the soil. Ensure that no roots show from the surface of the container.
Place the repotted ficus bonsai in a sink. Fill the sink with tepid water until the water reached approximately 1 inch past the trunk. Allow the ficus to rest in the water until the bubbles cease to rise to the top. Remove the bonsai from the water. Allow it to rest until the water stops flowing from the drainage system.
Place the ficus bonsai in a warm location that receives at least six hours of partially shaded sunlight each day. Keep the ficus bonsai away from cold areas, such as drafty doorways and air conditioners.
Feed the ficus bonsai from spring through fall with a well-balanced, slow release fertilizer such as an 8-8-8 or 10-10-10 combination. Distribute the fertilizer evenly around the tree at half strength. Keep the fertilizer away from the base of the tree to prevent root burn and rot. Irrigate the fertilizer into the soil. Never fertilize a dry or drought stressed tree.
Mist the foliage of the ficus bonsai to promote the desired humidity levels. Apply a fine-mist with a spray bottle filled with clean water. Mist the foliage evenly in the early morning to allow the tree a full day to dry under the sunlight.