Indoor bonsai trees are beautiful tropical or subtropical trees that can only be kept outdoors in a few climates. Unlike outdoor bonsai, these trees do not go into dormancy in the winter. Instead, they grow consistently all year. Indoor bonsai thrive in the high, stable temperatures of a standard living room. Because of the differences between indoor and outdoor bonsai, they have different care requirements. We will be going over the basics of caring for your indoor tree, including light, humidity, watering, and fertilizing requirements.

Caring For an Indoor Bonsai

Because bonsai trees are housed in such shallow containers, they have limited nutrient and water storage. So, caring for a bonsai tree is different from caring from a regular house plant. Taking care of an indoor bonsai is also different from caring for an outdoor bonsai. Outdoor bonsai have different light needs, as well as different watering and fertilizing preferences.

Light and Humidity

Tropical and subtropical bonsai trees like lots of light and high humidity. To get the best light intensity, place your bonsai tree directly in front of a south-facing window at all times. Moving the tree even a few feet away from the window will decrease the light intensity significantly. Eventually, this will weaken and kill your tree. 

Even when your tree is in the perfect position, it may not be receiving enough light. Grow lights can help provide your tree with enough light. Leave the artificial light on for around 10 hours a day. You can leave the light on for less time during the winter if you would like to mimic the changing of the seasons, but this is optional. 

Indoor trees also like high humidity levels. This can be hard to achieve indoors, especially if you use air conditioning or heating. Filling a humidity tray with water or wet gravel and placing it under your tree will help increase humidity. You can also try misting your tree a few times a day and opening a window during the day to allow air to circulate throughout your house

Watering

bonsai watering

While every tree has different watering preferences, there are some guidelines you can follow for every bonsai. The most important rule to follow is to never water on a routine. Instead, check your indoor tree’s soil every day and water only when the soil gets slightly dry. Watering on a routine can cause you to over- or under-water your tree, both of which could kill it. 

If your bonsai’s soil is dry, it is time to water your tree. To water, get a fine nozzle watering can and fill it with water. The fine nozzle will prevent the soil from being disturbed. Water generously until water starts to drip out of the drainage holes at the bottom of the container. Then, after about 10 minutes, water once more.

Rain water is the best water you can use when watering your tree, but tap water will work just fine.

Fertilizing

bonsai care

Since indoor bonsai trees grow consistently all year, they also need to be fertilized constantly. It doesn’t really matter what kind of fertilizer you use, so long as it contains nitrogen, phosphorus, and potassium. The fertilizer you use can also include other micronutrients, but nitrogen, phosphorus, and potassium must be the main three elements. A balanced liquid fertilizer is recommended for indoor bonsai trees. A balanced fertilizer simply means that the ratio of nitrogen, phosphorus, and potassium is 1:1:1.

Taking care of indoor bonsai trees is not as hard as one may think. Your indoor tree should be placed in a spot where it can receive lots of light, and a humidity tray can help with humidity levels. Under-watering and over-watering are big bonsai killers, but can be avoided as long as you water when the soil gets slightly dry, instead of on a routine. Fertilize with a balanced fertilizer as often as the directions suggest; usually it will be once every few weeks to a month. Once you get the hang of how to care for your tree, watering and fertilizing will become much easier. With proper care, your indoor bonsai should live a long and healthy life!