Why Are Bonsai Trees Small?

If you have ever had the pleasure of seeing a bonsai in person, you’ve probably started to wonder why they are so small. Are they just dwarf trees? Are they genetically modified? What makes them so teeny?

Let’s find out why are bonsai trees small.

Bonsai trees are small because we have made them small. If they grew in natural conditions, they would grow to a normal size for whatever kind of tree they are – but they are grown in a restricted environment, and therefore they grow to a far smaller size than the standard versions of that tree. Amazingly, they are just a miniaturized version that occurs in response to the conditions!

What Makes A Bonsai So Small?

Bonsai trees are small because of how they are grown, but how does this work?

Essentially, bonsai trees are normal tree seeds that have been planted into very tiny pots. The tree is kept in its tiny pot, rather than being potted into something larger as it begins to grow, and this restricts how large it can grow.

Baby Bonsai Tree

Genetically, a bonsai tree is exactly the same as a normal size tree. There is nothing different in their genes; their size is entirely based on the environment and the restrictions on their roots. A bonsai tree may be moved into a slightly larger pot as it gets bigger to let it expand a bit, but it will never be put in a big pot or unrestricted conditions.

If you were to take a bonsai out of its pot and plant it in the ground, it might well then grow into a full sized tree. This would depend a bit on how old the tree was; an old tree might not manage to grow significantly, but a young one would probably take full advantage and shoot upward.

This proves that bonsai trees are really just tiny versions of the normal trees we see in gardens and parks all over. It might be hard to believe that something so small could just be the result of the pot size, but it’s absolutely true – a bonsai is just a scaled-down tree.

Because humans love miniaturization so much, we’ve taken it to the extremes with these incredible plants and turned them into tiny but perfectly formed worlds. Part of the art of getting a tree to grow as a bonsai involves getting it to maintain its proper proportions so that it looks as much like a “real” (or normal) tree as possible.

Do Bonsai Trees Grow?

It might seem that something so small probably only grows for a few years and then stops, but this certainly isn’t the case. Bonsai trees will keep growing throughout their lives, although they often only grow in small amounts, little by little.

They can also live for an amazingly long time, sometimes hundreds of years. The oldest bonsai tree in the world is thought to be over a thousand years old – and of course, it’s still growing!

Bonsai growth tends to be hard to see because it is often very slow. Some bonsai trees may only grow in the summer months, while others will keep growing all year round.

Over time, bonsai trees will produce new shoots, come into leaf, grow branches, and flower. They have cycles and grow and change just like regular trees do – only on a very much smaller scale.

Growing Bonsai Tree

Often, the growers of bonsai trees have to prune them to help them stay in a healthy shape and make sure they don’t grow too much. The look of the bonsai is very important, and growers may remove extra branches, roots, twigs, and other parts of the plant that don’t make it very aesthetically pleasing.

With some kinds of bonsai trees in particular, the more established foliage will be out of proportion with the rest of the tree, and this may be pruned off to maintain the proportional look. However, growers may also prune other parts to keep the plant in the right size and shape.

The pruning, coupled with the slow growth, may make bonsai trees seem static and unchanging, but they grow just as other plants do.

Are Bonsai Trees Healthy?

Yes, bonsai trees are healthy. They are not made ill by being kept in such a small container; you can have a perfectly happy bonsai tree. It is important that other needs, such as water, light, and nutrients are met, just as for normal trees.

A good indication of this healthiness is just how long some bonsai trees can live. While the thousand-year-old one is one example, there are many others that live several hundred years old.

However, some trees will really struggle if you try to keep them as bonsai trees. They may not be able to deal with the root restriction and will probably die quite quickly if kept in small pots. 

It is important to find out whether a tree can cope with being turned into a bonsai before attempting to keep it in miniature. Common species for turning into bonsai trees include boxwood, ficus, juniper, and maple trees, but many other kinds can be grown in this way – you just have to know what you are doing!

Can A Bonsai Tree Produce Fruit?

Yes, amazingly, bonsai trees can produce fruit. However, before you go imagining the tiniest oranges, apples, and bananas in the world, there are a few things to bear in mind.

Firstly, remember that some kinds of trees do not cope well as bonsai trees. They need to grow to their full size and will not be healthy if their roots are restricted too heavily.

Secondly, fruits will not appear in miniature. The fruit produced by a bonsai may be somewhat smaller than the fruit produced by its full size counterpart, but it will not be miniature like the rest of the tree is.

Orange Fruit Bonsai

That might be a bit disappointing, but it is unfortunately just how it works. The tree may be tiny, but its fruits will be large.

If you care about aesthetics and proportion, you will probably want to choose fruiting trees that have small fruits, such as berries. On a bonsai tree, these will then look about the size of apples, and won’t seem out of proportion.

If you allow a bonsai tree with naturally large fruits (such as oranges) to bear fruit, it may look out of proportion and might require some extra support or risk broken branches. 

It certainly can still be done and some people like to do this because of the contrast that is created between the tiny tree and the huge fruit, but most people prefer to grow fruit that looks in scale with their little tree.

If you feel tempted to have a Bonsai fruit tree, check out this article on the most beautiful Bonsai trees that grow fruit.

How Big Can A Bonsai Be?

So, how large can a tree be before it stops being considered a bonsai tree? Are there any actual restrictions on this?

Many of us think of bonsai trees as things that could be held in the palm of one hand, two at most. Traditionally, bonsai trees were classed by the number of hands that would be needed to move them – so bonsai trees might be called “four handed” if they were particularly large, or only “one handed” if they were very small.

In theory, most bonsai trees are under a meter. Of course, this is not a strict science; it is an art form. There is a lot more to it than the height of the tree. The ratio of the trunk thickness, the spread of the branches, the overall look of the tree – all of these things make a difference, too.

However, in general, most bonsai trees are less than a meter, and anything over a meter would possibly draw some doubt in terms of its status.

According to the original classifications, bonsai trees would be categorized as:

  • Keishi Bonsai – if below 2,5 cm
  • Shito Bonsai – if below 7,5 cm
  • Mame Bonsai – if below 15 cm
  • Shonin Bonsai – if below 20 cm
  • Kifu Sho Bonsai – if below 40,5 cm
  • Chu Bonsai – if below 61 cm
  • Dai Bonsai – if below 101 cm
  • As you can see, the size is important in this art form, and Dai bonsai trees would be known as “four handed,” while Chu would probably be “two handed.” Below that might be two or one handed, depending on the size, spread, and weight of the tree.

    It may interest you to learn that the smallest of these sizes, the Keishi bonsai, is very difficult (or impossible) to maintain in the long term, and these are often the rarest bonsai trees. Usually, they will grow past this stage, and into one of the slightly larger stages.

    What Else Matters?

    The thickness of the trunk is also relevant to the size of the bonsai, as is the tree’s overall height. Many bonsai trees are encouraged to look ancient, and old trees are worth considerably more, so owners tend to try and train their trees to be tall, mimicking the spread of a mature tree.

    Although really anything goes as long as it is artistic, most bonsai trees have a ratio of 1:6 (all the way up to 1:12) between the diameter of the trunk to the tree’s height.

    That means that if you have a trunk of one centimeter, your tree might be from six centimeters to twelve centimeters tall, and this would be considered a standard ratio. However, there is a lot of flexibility and you don’t have to stick to this if you prefer not to!

    Where Did The Art Of Turning Trees Into Bonsais Come From?

    You may already know that bonsai trees originated in Japan, but that it is originally a Chinese tradition. The Chinese version tends to try and produce whole scenes in miniature, while the Japanese version focuses just on the trees and making them as proportional and realistic as possible.

    Bonsai trees have gained in popularity, spreading across the world, and many people are now fascinated by this art form. It really is an art, with people creating phenomenal living, breathing sculptures from plants.


    Bonsai trees are so small because we have grown them that way, and it’s as simple as that! By putting them in restricted pots, we force the trees to grow in miniature, and the more realistically the tiny version mimics the big version, the more successful the process is considered.

    If you have ever wanted to have a go at this, you can do it with almost any plant – so why not try it someday?