The Madagascar dragon tree, Dracaena marginata, is a popular houseplant as it has low maintenance requirements and it is easy to care for both as regular plant and as bonsai. It prefers to be pot bound, which makes it a good plant variety for growing under bonsai conditions. Purchase dragon tree plants that appear well rooted in their pots and have a firm trunk and healthy foliage. Bonsai pruning the root-ball every two years will slow the plant growth for desired results.
Place a potted dragon tree in an area that offers indirect sunlight conditions. Faded foliage is a symptom the plant is not receiving enough light.
Water the tree on a weekly basis when the top 1/3 of the soil becomes dry to the touch. Excessive leaf drop is a symptom of an under-watered plant, while yellowing leaves are a symptom of overwatering.
Fertilize the plant once per month during the spring and summer with a water soluble fertilizer. Do not fertilize during the fall and winter months.
Place a humidifier near the plant during the winter months to compensate for dry winter air. Mist the plant with water on a daily basis if a humidifier is not available.
Monitor the plant for the presence of spider mites on the leaves. The mites are visible by the naked eye and appear as small red spiders that produce white webs on the underside of the leaves. Isolate the plant and spray the leaves several times a day with water to remove the mites. Spray with insecticidal soap if necessary.
Wipe the plants leaves with a damp cloth to remove dust buildup.
Prune the roots of established plants every two years to dwarf the plant into a bonsai. Take the plant out of the pot and comb all roots growing around the root-ball. Prune thick roots and leave fine hair roots. Do not remove more than two-thirds of the root ball during a pruning session.