Do You Need A Grow Light For Your Bonsai?

Growing bonsai under grow lights is popular on social media, and I am probably part of the problem. I own two grow lights and I am always going on about how great they are and how my trees are growing so much better because of them.

But do you really need grow light for your bonsai?  Do I even need them?

Honestly, they do a great job, but for 99% of cases the sun in the sky will do just fine.

There are a lot of times when grow lights are the “better” option, but that does not mean that the sun is not good enough. 

Why Do We Use Grow Lights With Bonsai?

The only real reason to use a grow light for any plant, including bonsai, is so that you can have full control of the light levels. It’s as simple as that.

The sun is of course the better option. Letting nature do its thing is usually best, but sometimes you want to control it a bit more.

I live pretty far north and I also live in a quite wet and cloudy area. This means my levels of sunlight can be a bit low, which is not ideal for growing bonsai.

That doesn’t mean it is bad, it just means it not ideal. I have a number of tropical and Mediterranean bonsai trees that normally get blue skies and plenty of strong sun. Having a grow light allows me to control the light levels and give them a bit more than I can offer them outside and make it more like their natural environment.

There is nothing stopping me from growing everything I own with natural sun light. It will just be a bit slower and I have a little less control over how much light the trees can actually get. 

(you can read more about – How Much Light Do Bonsai Need?)

How To Decide If You Need A Grow Light for Your Bonsai?

If you do think you could benefit from a grow light then you need to look at a few different things and see if it makes sense for you to buy one.

What Is Your Climate Like?

Really you want to be working out how much sunlight you actually get and seeing what the quality of this light is.

For most of us, it will probably be enough, even for people like me. I live at about 55° North and I get more than enough light to grow things. I would imagine most of you reading this are a lot further south than this and therefore closer to the equator and you probably have a lot more light than you realise.     

What Is Species Of Bonsai Are You Growing?

The species you are growing plays a huge part in deciding if you need grow lights. Some species of bonsai need more light so you need to know what you are growing and where they like to grow naturally.

If you have a tropical species, it is probably going to need a lot more sunlight than something that is native in the UK. A tropical plant may also need this higher level of light all year round, which the sun outside cannot provide. 

Where Are Your Bonsai Growing Now?

You also need to assess where your bonsai trees are growing now. There is no point in looking at your climate and seeing you get 14 hour of sunlight if your tree is growing in a spot that is shaded all day. While the tree will still grow there, it is not going to grow as strongly as if it were in direct sun.

You may also have your bonsai trees inside, which for most trees isn’t going to be good enough.

Pretty much all bonsai trees grown inside will not have enough light. The problem is that some trees may not be able to cope with the low temperatures, or high levels of rain outside, so they need to be inside …where there isn’t enough light.

How Are Your Bonsai Doing Now?

You need to look at how your bonsai trees are growing now. Even if the conditions are not perfect, they are probably okay, so do you actually need a grow light?

If your trees are healthy, you might be okay without a grow light. If they are struggling, you need to ask what you can change to help them and one thing you might change is the light levels.

You might be able to simply fix the problem by moving the tree. That is the beauty of bonsai, they are portable.

However, you could just get a grow light and basically bring the better conditions to them.    

What Are You Trying To Achieve With Your Bonsai?

I think it is also important to ask yourself what you are doing with your bonsai trees. What is your goal and how does a grow light help that.

Some of us want to grow our trees out and thicken them up. To do this we need more growth. More light will make the tree grow faster and speed this whole process up, so a grow light can help.

If your tree is fairly refined and are you are just trying to keep it in shape, you might find you don’t need extra light and extra vigour in your tree. It may just be happy enough to slowly grow in the natural light.

Why I Got Grow Lights For My Bonsai

I think it’s better if I explain why I got my grow lights, using the points above. I thought about everything and for me it made sense.

Climate

As I’ve already mentioned, my climate is not great. We get a lot of grey skies and in the winter months the days are short and dark. In summer we actually get very long days, but the light is still not great.

There is a reason everyone in Ireland looks so pale, we get no sun. You will find we can still grow plenty of things here, but overall, my climate is not the best for growing bonsai.

Species

A large amount of my trees are native, or at least can tolerate my conditions here so they live outside. That is the best place for them.

However, I do have a number of succulents and tropicals as well as a few Mediterranean style trees.

The tropical’s are really not suited to here, but the Mediterraneans can handle it and I do have a lot of them outside.    

Where I Had My Bonsai Growing

I had all my succulents, tropical’s and a few Mediterraneans growing inside. I was trying to protect them from too much rain and it would be too cold for most of them during the winter, so I felt inside was best. The problem was, they were not getting enough light from the window.

How Were They Doing?

They were doing badly. It’s as simple as that.

They just did not get enough light and where struggling to survive. Let alone grow. In my previous house I had them in a big south facing window and while they did not grow amazingly, they where at least healthy as they did get a decent amount of natural light.

Where I had them growing now was too dark and it was a major problem, the trees where going to die if I didn’t do something.

What Was I Trying To Achieve?

I wanted my bonsai trees to be healthy.  I had two options, put them outside for more light, but then they would probably suffer from other things, such as too much cold and rain.

Or I could buy a grow light and keep all the other conditions the same. As lack of light was my only problem, buying a grow light seemed like the easiest way to fix this.

If I could go back to my old house where they survived just fine inside at the window, I would take that, but that’s wasn’t an option, so for me a grow light was the next best thing.

It corrected my problem very quickly and then actually gave me a lot of benefits. My tropical plants were now able to thrive and get the amount of light they actually needed and now they grow insanely well.

What Do Other Bonsai Growers Think Of Grow Lights?

I asked my YouTube subscribers if they use grow light and here is the results:

I am honestly surprised that 45% said that they used grow lights, I really thought that would be below 10%. Maybe this is just my audience, and the fact it was also a small sample size, but it is still surprising.

Maybe a more interesting study would be to find out if they all need these lights, by going through the points I have discussed in this article, but either way don’t just automatically assume you need one too.

Conclusion

If you go through the points above and answer the questions honestly, you should be able to work out pretty quickly if you need a grow light or not for your bonsai.

A lot of the time you probably won’t. Most trees are going to be totally fine with what nature can provide, but if you really feel they need that little something extra, a grow light probably will be able to solve that problem.

If you do end up buying one, you should read about – How to Grow Bonsai With A Grow Light