Do Bonsai Trees Need Light? Enlightening Facts Revealed!

  • By: Josh Koop
  • Date: September 10, 2023
  • Time to read: 5 min.
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Whether to use natural or artificial light is a common question that comes to the minds of bonsai enthusiasts occasionally. Questions like, do bonsai trees need light are also quite common. Thus, this article addresses your most common concerns about bonsai lighting.

Bonsai trees need light, especially UV rays from sunlight, which helps retain good health. Maintaining proper lighting according to the type of bonsai is vital, too. Indoor bonsais can make do with artificial light, but outdoor ones will most certainly require sunlight.

However, that’s not all that you need to know. Given that lighting for bonsai trees can be a tricky issue for new growers, it’s always a good idea to have some relevant knowledge regarding the subject.

That’s why I’d recommend you stick around till the end of the article!

Bonsaid isolated ona desk against a wall backdrop

Can You Grow Bonsai Indoors With Only Artificial Lights?

In other words, yes, it is very much possible. Indoor bonsai trees are usually from tropical climates, where the temperature outside usually remains steady throughout the year. Thus, bonsai trees meant for indoors can survive with no hassle using only artificial light. However, choosing the right type of artificial light is crucial to ensure proper growth.

Artificial light can be of three types: fluorescent, HID, and LED. These types of lights will be discussed further below to give you a more profound idea. Each type of light has unique features and recommended application settings.

Fluorescent lights: These lights are placed near the canopy of bonsais but kept at least 8-10 inches away to ensure the leaves don’t get burned.

These lights are usually low-maintenance and do not cause much fuss when it comes to controlling the temperature. Make sure you stick to 5000K CFL T5/T8 fluorescent bulbs for starters.

HID lights: HID stands for “High-Intensity Discharge.” These lights pack quite a punch in terms of power and are also very efficient.

However, it comes with a price as their high-penetrating powers can become challenging to deal with as they can raise the room’s temperature due to their intense lights.

Hence, HID lights are suggested to be positioned 20-24 inches away from your bonsai. The location of your bonsai must be well-ventilated to make up for the excess heat-storing up as well.

Nevertheless, the nature of these lights is perfect for stimulating external growth, such as vegetation and flowering.

LED lights: Light-emitting diodes are the complete package regarding lighting, efficiency, durability, and naturality. They are also quite budget-friendly and do not cause any strain on the bonsai.

They are the perfect mix-and-match love child between fluorescent and HID lights. A 10-inch space between the bonsais is usually sufficient.

While indoor trees must be kept indoors to survive, it is conceivable that they require at least some direct sunlight throughout the day to grow.

It is also beneficial to supply artificial illumination to indoor trees if they are not receiving enough light due to problems associated with positioning.

How Much Artificial Light Do Bonsais Need?

As a rule of thumb, bonsais usually require 5-6 hours of indirect or direct light a day. However, the hours can vary depending on the type of species you are keeping indoors and the intensity of the provided light. For example, indoor bonsais sometimes require 16–18 hours of fluorescent light. This is similar to any indoor bonsai that is reliant on artificial lighting.

If you provide light indirectly to your bonsais, exposure to this number of hours of artificial light is mostly complemented by placing these indoor bonsais in a south-facing window. However, this can vary for outdoor bonsai if they are prone to dormancy.

That is all regarding the question, “do bonsai trees need sun, bonsai grow light?” More information regarding artificial light and sunlight is presented below.

Artificial Light Vs Sunlight For Bonsai

Let’s do a direct comparison to better understand this topic. What exactly sets each of them apart and how they have complemented the existence of certain bonsai species is unclear.

To start, let’s focus on differentiating between these two bonsai lighting methods.


Bonsai require direct sunlight to produce their food. Thus, the majority of bonsai trees need at least 5-6 hours of exposure to sunlight per day. A lack of regular exposure to sunlight can damage a bonsai in so many ways.

If an outdoor bonsai doesn’t receive enough sunlight throughout the day, it will soon begin to show signs of damage, such as weak foliage, wilting, and falling leaves.

Exposure to sunlight can be either direct (raw exposure to sunlight) or indirect (barriers such as windows filtering much of the sunlight’s intensity).

Usually, outdoor bonsai trees thrive in direct sunlight, but some species of indoor bonsai trees can thrive in indirect sunlight better. 

Even indoor bonsai trees will require sunlight exposure during summer to get an adequate supply of raw UV light, which helps distribute nutrients. However, in most cases, indirect exposure serves these bonsai better.

Artificial Lighting

It’s the type of light that can be controlled in terms of intensity and distance. It is mostly the go-to option for indoor bonsai species that do not get sufficient sunlight.

Depending on the season, you can alter the exposure hours to artificial light on your bonsai.

Artificial lighting can also be used to treat the needs of some outdoor bonsai species that become vulnerable to direct sunlight exposure depending on temperature changes.

Some trees lose their leaves due to dryness due to direct exposure and, hence, need to rely on artificial lighting or indirect sunlight to stay on track.

Although nothing replaces direct sunlight, artificial light is quite a promising candidate with its own price. They usually come with external coatings such as electricity and maintenance.

However, if properly set up, they can supply ample of the required light to keep the bonsai functioning naturally.

Artificial lighting is crucial for tropical bonsai trees that are extremely vulnerable to the elements of the winter season outdoors.

Bonsai Needs Some Darkness As Well

Flaming exposure to high-intensity UV rays does not always solve the problem for all bonsais. Regarding delicate plants like bonsai, too much of something can be damaging in the long run. Overexposure to sunlight can cause burns and, sometimes, even dry up leaves.

In terms of indoor and outdoor bonsai trees, none require you to keep providing lighting 24/7. A fixed amount of exposure with proper positioning and lighting will suffice to meet the basic demands.

The amount of darkness required by bonsai trees varies depending on the species and the seasonal change taking place.

Indoor bonsai may require far less artificial light on cold winter days than usual. However, during summer, it’s better to upscale the time limit for exposure to sunlight.

Even outdoor bonsais require bringing them inside on winter days to ensure survivability.


That pretty much sums up the importance of lighting and its basic aspects when it comes to growing bonsai trees. If you wish to learn more, do check out more articles on our website regarding bonsai.

We wholeheartedly encourage anyone to participate in this beautiful journey of growing a bonsai. I wish you all the best for your adventures, and thank you for your time!