Ficus bonsai are indoor bonsai trees that grow very slowly. They are fairly low-maintenance plants, particularly when it comes to watering. Ficus bonsai trees require infrequent, but thorough, watering. As long as it is not over-watered, your ficus bonsai tree should avoid many of the diseases and pests that can plague this plant. The most important thing to remember when watering a ficus bonsai tree is to check the plant's dirt every day to make sure it hasn't dried out too much.
Sink the tip of your finger about an inch into the dirt in the ficus bonsai tree's pot. If the dirt feels damp, hold off on watering the plant. If the dirt feels dry and dusty, it's time to water.
Fill a bowl with several inches of cool water and place the ficus bonsai tree's pot in the bowl. The water should completely cover the pot and dirt and reach the base of the tree's trunk.
Allow the tree to soak in the water for about 10 minutes. Lift the pot from the bowl and allow the excess water to drain from the holes in the bottom of the container.
Place the ficus bonsai tree on top of a drainage plate. Check the plate after an hour or so and discard any water that has settled on it.
Repeat this watering process whenever the ficus bonsai tree's dirt feels dry. For best results, check the tree's moisture level daily. Sitting in dry soil for an extended period of time can damage the plant.