Bonsai Light Needs: How Much Light Do Bonsai Trees Need?

If you have a bonsai tree, you are already probably spending time thinking about how to ensure it has the best possible conditions, and we all know how crucial good lighting is to a plant. So, how do you know how much light to give to your bonsai tree? How much light do most bonsai trees need?

Unfortunately, the amount of light needed will depend on the tree species that is being grown. Most bonsai trees need five hours of light per day or more, but some kinds may require extra amounts of light in order to thrive and grow healthy. Providing enough light to your bonsai will ensure it grows straight and has plenty of energy.

How Much Light Does A Bonsai Tree Need?

Although it can be difficult to generalize, because a bonsai can be almost any kind of tree at all, most bonsai trees will benefit from five or more hours of sunlight each day. They prefer direct sun, almost universally.

Bonsai plant with direct sunlight

This is because the full-size version of the tree will be a light-lover. Trees, being so much taller than other plants, have evolved to gather as much light as they can, and they are rarely damaged by too much sun. Their leaves should be able to cope well, even if you put them on a windowsill in full sun.

However, if you do notice burning, make sure that you move the tree further away from the window, or put up a thin curtain to protect it.

Why Do Bonsai Trees Need Light?

All plants need light, and bonsai trees are no exception to that rule. Without light, plants cannot complete some of the basic functions that they must be able to complete to survive.

Light is necessary for plants to photosynthesize, and through this, they make the energy that they need to sustain themselves and to continue growing. With insufficient light, growth will be stunted or will halt altogether, and the plant may start to die.

It is also essential for a plant to respire properly. If a bonsai tree is not given enough light, it cannot produce the sugars required for respiration, and without respiration, it will die. Plants use this process as a means of breaking down food into carbon dioxide and water, releasing energy. The plants then use this energy to keep growing. Both photosynthesis and respiration are crucial.

Insufficient light will result in the death of the plant, so it is important to consider how much light your bonsai tree gets.

Will My Bonsai Tree Need A Grow Light?

This depends on your location and the time of year. In many parts of the world, bonsai trees will flourish even without a grow light, provided that they get plenty of natural light. However, if you live in a part of the world with shorter days, you may find that your tree needs a grow light, especially in the winter.

You should check how much light your bonsai tree is getting in a day, and if it isn’t getting five hours or more, consider moving it to a new location or installing a grow light nearby. You can then turn the grow light on whenever the light conditions are too low to keep the tree happy.

Can I Grow A Bonsai Tree With No Sunlight?

Have you ever wondered whether you can grow a bonsai tree in a completely lightless room, provided you have a grow light for it?

You may be able to do this, but you will need proper lighting and not just any old light bulb. You can try the following light options.

HID Lights

If you are looking to stimulate lots of leaf growth, a High Intensity Discharge light might be suitable. These lights will help to provide enough energy for your bonsai plant to grow, but they do take a lot of power.

You need to make sure that the lights are not too close to the plant, because they generate quite a lot of heat. Allow about twenty-five inches between the plant and the light to ensure that the plant doesn’t get burnt or too hot.

LED Lights

LEDs are a popular form of lighting for keeping your plants happy because they are a strong light source but they do not use nearly as much power, and this reduces the household costs of growing your plant.

They also do not produce too much heat, which makes them far more suitable for using near to a plant. You still should not get them too close, but if you have a 50 watt LED, it should be safe up to ten inches from the tree.

LEDs have the additional advantage of lasting for a long time, and their spectrum is the closest that a bulb can provide to the sun’s spectrum. That means they are probably the best replacement that there is for sunlight. They are also reducing in price all the time.

It’s a good idea to look for an adjustable LED light that provides the full spectrum – as opposed to just some of the spectrum – so that it can help ensure your bonsai tree grows healthily.

Fluorescent Lights

In a pinch, you can use fluorescent lights for your plants, but you will need to keep them on for most of the day. Usually, they must be run for sixteen to eighteen hours if they are to successfully provide enough light for the plants.

Again, these can be used reasonably close to the plants, because they do not give off a lot of heat. They won’t dry the plant’s soil or make it too hot, which makes them pretty good for low-maintenance growing. 

These lights should be kept about ten inches away from the plant. Keep an eye out for any singed leaves on your bonsai tree, and move the plant further away from the bulb if it is looking heat-damaged.

Where Should I Put My Bonsai Tree Inside?

Although you can grow a bonsai tree in artificial light, natural sunlight is still the best option. If you have a windowsill that you can place your bonsai tree on, use it because your tree will thrive with lots of natural light to keep it growing and allow it to photosynthesize.

It’s a good idea to rotate your bonsai tree regularly. Light from a window usually only hits one side of the tree (unless you have a skylight), which means that the tree will lean toward the light, resulting in a crooked bonsai.

Bonsai Plant next to a window

By turning your plant, you encourage it to grow upright and keep it healthy and aesthetically pleasing.

You should also make sure that your bonsai tree is not too close to a heater, a radiator, or a window or vent. Sudden temperature fluctuations or too much heat or cold air could very quickly kill your bonsai tree, especially if it is a sensitive species.

Because the pots are so small, your tree’s roots will not have much protection, and even a tree that is usually cold hardy will struggle to deal with low temperatures for long. Don’t risk your bonsai tree’s survival by putting it in a cold or a hot place unless you know it is hardy enough to survive.

On the whole, bonsai trees prefer to be kept warm, rather than cold, but be aware that some bonsai trees cannot be grown indoors because they need a period of dormancy, and this is triggered by the cold of the outside world. Without this, the tree will probably die.

Which Bonsai Tree Should I Have?

Some bonsai trees are fussier and much harder to grow than other ones. If you aren’t sure whether you can provide much natural light inside your home, it’s important to look at the kind of tree that you are planning to grow, and determine whether it will survive in your home.

How do you do this? The best way is to select a bonsai tree that is already well-suited to being grown inside (because some bonsai trees will not grow well in a house). Some species will thrive even if they are getting the more limited light available.

Some of the bonsai trees that you could try growing in your home include:

  • Chinese Elm
  • Ginseng Ficus
  • Jade
  • Hawaiian Umbrella
  • Carmona
  • Serissa Japonica

Choosing a variety of bonsai tree that is easy to grow massively increases your chance of success. It is important to do some thorough research into the kind of tree that you plan to get because this can make a big difference to the amount of light that it needs and the level of care that you will have to provide.


Although their needs can vary, most bonsai trees require over five hours of light in order to grow well. Light with the full spectrum, such as sunlight, is better for your plant than the partial spectrum light provided by some bulbs. However, a grow light can be used to supplement the sun and help the plant to keep growing in low light conditions.