Is Bonsai Cruel? What the science says

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Bonsai trees have been a bit of a miracle for me over the past few years. Not only has caring for and designing the trees improved my mental health, but I’ve also acquired many skills that I transfer to my garden. As such, I was a little taken aback by the recent upswing in the disadvantages of bonsai and people arguing that bonsai trees are cruel. So is bonsai cruel? 

Growing, pruning, or designing bonsai is not a cruel practice. Bonsai trees do not have pain receptors, a brain system, or consciousness and cannot feel pain.

So are there any arguments in favor of bonsai being a cruel practice? And what can you do to ensure you are not abusing your trees? Keep reading to find out more. 

Just a quick heads up, over the past three years of running Plantpaladin, hundreds of people have asked for product recommendations. As such, You can find my favorite indoor bonsai tree here (link takes you to Bonsaiboy), my favorite outdoor bonsai tree (link takes you to Bonsaiboy), or have a look at all the products I recommend here. 

Is bonsai cruel?

While bonsai trees can have a wealth of benefits, we can sometimes forget about the impact that we are having on the trees. 

After all, it makes logical sense to think that the wiring, damaging, and twisting we undertake on our bonsai tree can be deemed cruel. 

Over the past few years, there has been a more prominent presence of people arguing on the side of flower power and that plants and trees should only be grown in their natural environments and left to grow freely. 

Like you, the last thing I want to do is cause unnecessary harm to my bonsai trees. 

As such, I undertook a deep dive into the scientific literature behind bonsai trees feeling pain, got in touch with a few bonsai experts, and even surveyed ten plant paladin readers to get to the bottom of if bonsai is cruel. 

To summarize: 

Is bonsai cruel?- quick facts

• Bonsai trees are not cruel practice, specifically growing, pruning, wiring, and developing bonsai trees. 
• This is because bonsai trees, like all trees, do not have pain receptors, a brain stem, neurons to send signals, or a brain to determine how much pain they are feeling. 
• As such, bonsai trees cannot feel pain and so do not care if you transform a tree into a bonsai tree. 
• Most of the scientific literature and studies on trees and plants feeling pain determine that while some trees can sense and react to stimuli, such as a caterpillar walking on the leaves of trees, this does not equate to the tree feeling pain. 
• While a few studies argue in favor of bonsai trees feeling pain, the scientific methodology is spotty and more hypothetical at best. 
• To have peace of mind that you are not being cruel to your bonsai, only wire and prune the tree during the spring or summer, so your tree has plenty of time to recover from invasive training techniques. 
• Aim to water, provide enough sunlight, and try to grow your bonsai tree species in a similar climate to where it originated. 
• I would also recommend only training the tree when the tree is old enough to recover from the growth, such as after the three to five-year mark. 
• Avoid training bonsai trees that are exceptionally old such as over 200 years old, as this can damage the tree. 

Now, this is quite a lot of information to take in, so let’s break this down in more detail.

Why do people think bonsai is cruel? 

So let’s start with the main arguments that some people have as to why bonsai is cruel: 

Wiring 

The first central and most common argument that people have when it comes to bonsai being cruel is wiring the tree. 

To have a truly stunning and aesthetically pleasing bonsai tree, we need to grow our trees in a specific style. 

These styles can include things like cascade, semi-cascade, or sumo. 

Wiring is undertaken to hold the bonsai tree in position to grow its branches to achieve these intricate designs. 

The argument that people opposed to bonsai make is growing a tree in this way is unnatural. 

You would not bind a person like this to grow, so why do the same for a tree?

On top of this, the wire typically used for bonsai trees is most commonly made of copper or aluminum. 

If not disposed of correctly, these wires, especially copper wires, can adversely impact surrounding trees. 

Copper nails, for example, are commonly used to kill trees. 

How to make this less cruel? 

Now, if you are opposed to using copper or aluminum wire, the good news is that there are several alternatives that you can use. 

Bamboo, thread, yarn, or jute rope are all-natural alternatives that can be used to wire your bonsai tree and do not impact the surrounding flora. 

Constricting to a pot 

When growing a bonsai tree, one of the ways the miniaturized state of the trees is contained is by keeping them in a shallow pot. 

For example, Ficus, Elms, Junipers, Olive, and Oak trees can all grow well over 2 meters tall in the wild if planted in the ground. 

However, keeping them in a pot will stunt the trees’ growth, and the bonsai roots will only spread out slightly before hitting the wall of the pot. 

While keeping bonsai trees in a pot seems like locking your tree up in jail, there are a few caveats. 

First, most of the bonsai trees on sale today are designed to grow to a smaller size.  

It’s one reason why common Elm trees are rarely used in bonsai, but Chinese elm trees – a species that has been bred for thousands of years specifically for bonsai are used so frequently. 

On top of this, bonsai trees and even the most petite bonsai tree sizes, such as fingertip-style Keshitsubo bonsai trees, will still be repotted frequently.  

Most bonsai trees are repotted once every one to two years on average. 

Any worries people have about the roots of a bonsai tree being crushed on your bonsai trees not being able to absorb nutrients from the soil correctly are quickly negated. 

While it is more uncommon, some bonsai trees can benefit from being planted in the ground, such as when they become overwatered or root rot starts to sprout. 

If you are hesitant about keeping your bonsai in a pot, consider planting outdoors for peace of mind. 

Growing in their unnatural conditions 

Another central argument against bonsai trees and for bonsai being cruel is growing the trees in their unnatural environments.,

For example, Most species of Ficus or Jade are tropical or desert trees and prefer to be grown in brighter, warmer climates. 

As such, the argument stands if you are growing a ficus, say in the UK, in much cooler, milder conditions not suitable. You are putting more strain on the tree than is needed. 

The truth is, however, that most bonsai gardeners agree 100% with this statement, which is one of the reasons we try to match the climate and conditions of our trees as best as possible. 

Another reason why ficus trees are grown indoors is to benefit from warmer conditions compared to milder outdoor conditions. 

On top of this, many bonsai enthusiasts will purpose-build greenhouses to house their more tropical bonsai species. 

Most of the common species of trees used in bonsai have also been acclimatized to grow in pretty much any conditions, which is one of the reasons trees like Chinese elm and ficus are so beginner friendly. 

Pruning and cutting 

Pruning and cutting a bonsai tree is a natural part of growing bonsai. 

These activities are most often undertaken when the tree branches or overall size get too big and need to be trimmed.  

The argument that many have is that pruning and trimming bonsai trees too frequently will cause the tree to become weakened and not be able to recover. 

As such, many bonsai tree owners take extra care when pruning and trimming the trees and only do so in a few critical situations: 

• When the tree is old enough to recover from the pruning 
• During the early spring or summer, so the tree has time to recover 
• During every other growing season 
• Not undertaken on older, slower, growing trees. 

On top of this, the most common bonsai species will only grow about 1 to 12 inches per year during the growing season, meaning that pruning is usually only done once per year and not a week in week out occurrence. 

Trunk development and deadwood techniques

In more complicated bonsai tree designs such as the semi-cascade, wiring and pruning alone will not be enough, and often widening the tree trunk or using deadwood techniques such as creating Jin are often needed for a visually impressive tree. 

Now, these techniques often require chipping the tree’s trunk altogether or using specialist tools to drill and gut out the inner wood of the tree. 

While this sounds a little brutal in the first instance, like wiring and pruning, these techniques are undertaken sparingly so the tree can recover and not be undertaken on weaker or younger trees.  

These techniques, too, are often paired up with glues and epoxies to prevent the tree from being infected with bacterial infections. 

Impact on other plants

The final prominent argument people have against bonsai trees is that they can negatively impact surrounding plant life. 

For example, if you are growing a fruit bonsai tree such as an apple bonsai. This will increase the likelihood of insects such as aphids, scale,  and caterpillars infecting surrounding trees. 

While it’s no secret that some species of bonsai can attract creepie crawlies, this would be no different than it would be in the wild. 

On top of this, bonsai trees are kept in pots, making it easier for you to isolate and identify the insects attacking your trees. 

In the wild, insects are commonplace to infect tree after tree, so one significant advantage of bonsai is that you can easily prevent this from occurring. 

Growing bonsai trees in pots will also mean that you won’t have to worry about your tree absorbing or attacking away valuable nutrients from the soil of surrounding trees. 

Arguments against bonsai being cruel 

So we have covered the arguments against keeping bonsai trees, but what are the major arguments against bonsai being cruel? 

Trees do not feel pain 

The biggest argument against bonsai being a cruel practice you can undertake on your trees is simply that bonsai trees, or all trees for that matter, do not feel pain. 

We will cover this in a little more detail later in the post, but bonsai trees do not contain the brain, sensory system, or nervous system to feel pain. 

Some studies show that plant life can react to stimuli such as a mild electric shock or a caterpillar walking against the tree’s leaf, but physical pain that causes the tree discomfort has not been observed. 

Been practiced widely for thousands of years with no uproar 

Keeping bonsai trees as a practice has been commonplace for well over a thousand years. 

While we should continue not everything from the past in today’s times, the benefit of bonsai being practiced for so many years means that best practices for keeping trees as healthy as possible during the miniaturization process are now commonplace. 

Due to this timeline – some species of tree have been crossbred (for lack of a better term) to produce better bonsai trees. 

Helps with mental health 

Taking a step away from the harm of the tree for a second, we often forget the impact that gardening can have on the people who own them. 

Numerous studies have found a positive correlation between those who garden and undertake bonsai and improved physical, mental, and emotional health. 

One post from the UNC found summarized a few studies with the following benefits: 

• Improved self-esteem 
• Better heart health 
• Stress reduction 
• Better mental health 
• Higher levels of happiness 

Training only happens at a limited period

Another argument against bonsai being cruel to the tree is that training a bonsai only really happens during limited periods during the year. 

For most tree species commonly used in bonsai, most of us will only prune, plant, and repot our trees during the spring and summer. 

This is mainly done when the trees are old enough to handle any training and not undertaken on younger or older trees that can be more delicate. 

On top of this, let’s say you were to grow out a sacrifice branch to help thicken the trunk of your bonsai tree. 

You would grow a sacrifice branch for 2 to 3 years, where your tree would be left alone to grow. 

Most people have an image that we are fidgeting with bonsai trees daily, but the truth is they only really need our attention once in a while. 

Now compare this to digging up or rerooting common garden weeds, which is undertaken a lot more frequently, then you could argue that doing so to these weeds is much crueler than growing bonsai. 

Prevents insects from eating trees 

We touched upon this point already but keeping your bonsai tree in a pot makes it much more visible for you to notice insect infestations. 

This means that you can treat all insects either through natural predators or pesticides. 

You can do this without worrying that the insects from your bonsai will transfer over to the other trees, as most bonsai trees are smaller and easier to carry away. 

Do bonsai trees feel pain? 

Like all flora, plants, and tree life, Bonsai trees do not feel pain. Bonsai trees lack the pain receptors, brainpower, or nervous system to feel the pain that animals and other fauna have. 

Now I’ve written a separate post about if bonsai trees feel pain, which you can read up more on here. 

The general argument, however, is that while some trees can feel general sensation – or have some responses (such as a venus fly trap closing its leaves to engulf a fly)

They do not have the brain capacity or consciousness to feel pain. 

What do the studies say? 

Now I’ve also listed a few studies below; while the vast majority declare that trees do not feel pain, a few do argue the alternative, so in the interest of full transparency, I’ve listed them below: 

Is cruelty the right word to use? 

So one part of the argument around bonsai being cruel that we have to contend with is the word cruel. 

While we have covered if bonsai trees feel pain, pain and cruelty are not equivalent. 

I like to think about it as digging up the earth for oil. 

While the earth, rocks, and soil do not have feelings or care that oil companies dig up the ground in search of crude oil, if we dig up too much earth or take out too much oil from the ground, then this can have a severe impact on an ecosystem. 

As such, it is our responsibility as the most intelligent creatures on this planet to look after life, both conscious and non-sentient. 

The same then goes for bonsai trees.

While the practice of wiring, pruning, and trimming is not painful to the trees, if we are deforesting thousands of Chinese Elm trees from their natural habitat to grow bonsai, then this is something we should all consider. 

How to care for a bonsai in a cruelty-free way? 

So while it is not cruel to keep a bonsai tree, there are some tips you should follow to ensure that you don’t overburden your tree. 

Following these tips will ensure your tree stays healthy: 

• Water your tree frequently – once to twice per week is plenty for most bonsai – ensure you do so when the topsoil of your tree is dry to touch 
• Provide adequate sunlight – most bonsai trees love sunlight, so aim for your tree to get between 4 to 8 hours of sunlight directly. Consider investing in grow lights if you keep your tree indoors. 
• Check regularly for pest and mold infections – once per week is usually enough to keep on top of your tree. 
• Do not overtrain your tree – only wire, prune and train your tree during the spring and summer months when your tree is old enough to recover. 
• Provide nutrient-rich soil – use an organic or inorganic soil mix that provides enough water, moisture retention, and air for your tree. 
• Repot when your tree outgrows its pot – Aim to repot your bonsai every 2 to 3 years for most species. 
• Aim to match your bonsai tree’s natural climate and temperature to thrive. 

Is bonsai mean to trees? 

Bonsai is not mean to trees. This is because bonsai trees, like all plants and trees, do not feel pain or have a consciousness, so they cannot feel emotions one way or another. 

While some studies who that trees can feel sensation, it is doubtful they care if they are cut, wired, or pruned. 

Where did the argument about bonsai trees being cruel start?

Having researched thoroughly then if bonsai is cruel or not, people primarily formed this argument by anthropomorphizing bonsai trees. 

As we all agree, binding, trimming, or wiring an animal would be something none of us would think of doing. 

As plants are living organisms, it can be natural to think that you wouldn’t do this to an animal, so why do it to a tree?

The truth, however, is that there is no scientific basis for the argument of bonsai trees feeling pain, so the argument of bonsai being cruel is somewhat of a moot point. 

Survey results 

Finally, I wanted to finish by asking ten plant paladin readers if they thought keeping bonsai trees was cruel. 

Here are the results: 

My top picks for the gear you will need!

So like I mentioned earlier, over the past three years of running PlantPaladin, hundreds of people have asked me for my recommendations on the best bonsai gear on the market. 

Having spent thousands of dollars on bonsai items these past few years and tested at least 100 bonsai-specific products, I’ve listed my favorite products below – All of which I highly recommend and think you can get great value. 

They can purchase directly by clicking the link to take them to Amazon. 

Bonsai Tool Set: One of the significant challenges I’ve had is finding a toolset that was not only durable but didn’t break the bank. SOLIGT has recently developed a fantastic bonsai tool set that covers all the tools you need to trim, prune, and repot your trees. – You can grab it here. 

Complete Bonsai Set: Many of you will want to grow your bonsai trees entirely from scratch, but finding the varicose seeds, pots, and other items in one place can be challenging. Leaves and Sole then have created a complete bonsai set that I’ve personally used that ticks all the boxes. You can grab it here. 

Bonsai wire: The number of times I’ve run out of wire for my bonsai or purchased cheap bonsai wire that doesn’t do the job is embarrassing for me to admit. After a lot of trial and error, I found that using Hotop’s aluminum bonsai wire is one of the best options on the market. This can easily be used for both indoor and outdoor bonsai. You can grab it here.