Light is crucial to the health of your bonsai tree. But does it matter whether the light these trees receive is direct or indirect? The answer to this question depends on several factors. Some bonsai trees only need direct sunlight, while others do very badly in direct sunlight. In this article we will be going over whether outdoor bonsai need direct light, whether indoor bonsai need direct light, and the difference between direct and indirect sunlight.

Outdoor Bonsai

Outdoor bonsai trees need to be exposed to the seasons in order to survive. Therefore, most of them need lots of direct sunlight throughout the day. On average, outdoor trees need about 5 hours of direct sunlight per day. 

An example of a tree that needs lots of direct sunlight would be the Juniper bonsai. Juniper bonsai are not able to live indoors because the light intensity is too low for them. 

Japanese Maple and pomegranate trees are examples of outdoor trees that do not like direct sunlight all day. These trees like to be placed in shade in the middle of the day when temperatures grow hotter. This will ensure that the tree’s leaves are not damaged from the sun.

Indoor Bonsai

Many varieties of tropical or subtropical bonsai trees grow best indoors. These trees will usually need some form of artificial lighting, but they can also benefit from being placed outdoors for a few hours a day in the summer. 

Trees like the Jade and Ficus bonsai can be placed outdoors in higher temperatures. When placed outside, they do not like a shady position. Direct sunlight is very favorable to these trees.

In contrast, Dwarf Umbrella and Sageretia bonsai trees do not like direct sunlight outdoors. The dwarf Umbrella tree does not like to be taken outside at all. This subtropical tree is only an indoor tree, never an outdoor tree. Sageretia trees also do not like direct sunlight when placed outside. They like to be placed in shade.

Direct vs Indirect Sunlight

Knowing the difference between direct and indirect sunlight can help you grow your tree the right way.

Direct sunlight occurs when sunlight hits your tree directly, with no barrier between the sun and the tree. This ensures your tree is getting the most intense light possible. Some trees need lots of direct sunlight to survive, while others will dry up under this amount of light.

Indirect sunlight occurs when sunlight is not directly hitting your tree; there is a barrier between the sun and your tree. An example of this would be light hitting your indoor tree through a window. Indoor bonsai trees can survive on indirect sunlight, but this is rarely enough. These trees will usually need help from artificial lighting as well.

Artificial lighting, another type of lighting, can be as intense as direct sunlight, but it is used indoors. Artificial lighting can be used on indoor bonsai trees that are suffering from low light intensity. To increase light intensity, turn on this light for around 10 hours a day every day. It may be helpful to mimic the changing of the seasons with this light. For instance, you can run the lights for longer in the summer, up to 16 hours a day, and shorter in the winter for around 5 hours a day.  

Light intensity can make or break a bonsai tree. Some trees are more tolerant than others, but some specifically need direct or indirect sunlight. Most outdoor trees need direct sunlight all year, even in the summer, while others are sensitive to hotter days and should be placed in shade or partial-shade in the summer. Direct lighting can cause leaves to dry out on some trees. While indoor trees need to be placed indoors in order to survive, it is still possible that they need at least some direct sunlight during the day to thrive. It also helps to provide indoor trees with artificial lighting if they are not receiving enough light. You should be able to visibly see when your tree is receiving enough light: it will look healthy, happy, and strong.