Plant your bonsai in a well-drained container that meets the size requirements of the tree's current size. Though the tree will adapt to most soil types and conditions, the ficus bonsai tree prefers a nutrient rich, sandy loam. Create the loam by mixing one-third compost with two-thirds soil. Ensure that the container includes a drainage system that allows excess water to exit.
Place your ficus bonsai in a partially shaded, indoor location. The ficus bonsai requires the combination of water and sunlight to produce its required nutrients. Still, the tree's foliage is tender and susceptible to foliage burn when placed in the hot sun. Choose a location that provides an average of four hours of morning sunlight. This will provide the tree with the sunlight it requires without the heat of the midday intensity.
Water your bonsai regularly but do not over water. The ficus bonsai prefers to dry out between each watering and can tolerate short periods of drought. Avoid over watering by checking the soil's moisture levels first. Place your finger about an inch into the soil near the root system. Water your tree if the soil feels somewhat moist to dry. Most ficus bonsai trees require watering about twice per week. However, develop your tree's watering schedule based on the needs of the tree.
Fertilizer your bonsai every two weeks during its growing season. Use a wellbalanced fertilizer that includes nitrogen, potassium and phosphorous. Incorporate the fertilizer into the soil of the tree. Avoid placing the fertilizer directly onto the roots of the tree since this will cause root burn. Do not fertilize the ficus outside of its growing season, from late fall through winter's end.
Inspect your ficus bonsai tree regularly. Check the tree for signs of insects and disease. Spider mites are common predators of the ficus bonsai. If your inspection reveals small webs, yellowing leaves or spots, spray your tree with an insecticide to eliminate the pest. Check for signs of disease, such as yellow or browning foliage, branch or stem dieback, wilting or stunting growth. These are signs of potential disease or malnutrition. Check with your nursery or horticultural specialist for assistance in defining the correct treatment.
Dust and mist your ficus bonsai's foliage daily. Bacterium and fungal spores travel through the air and land on surfaces, such as plant foliage. Dusting the foliage will reduce the potential from disease. This tree prefers a humid environment. Most indoor environments are filled with dry air. Misting your bonsai's foliage will counteract the humidity. You can also place a humidity tray under your ficus to balance the humidity level.
Prune your ficus bonsai tree's branches, stems, foliage and roots to promote a miniature size and intended shape. Trim back new growth to promote vigorous growth. However, avoid pruning all of the new growth in one session since this could stunt the tree's growth and promote dieback. Repot your bonsai yearly or when the tree shows signs of outgrowing its current planter. Prune its roots during the repotting process.