Why Do People Put Stones Around Bonsai Trees?

If you have seen any of my youtube videos you may have noticed that some of my trees have stones around the base and I am often asked what that this is all about, which I will explain here.

You will often see people using either small or large stones at the base of their trees and this is simply for aesthetics or structural support, but I will get into more detail below.

Large Stones Are For Support

If you see some large stones around the base of a bonsai tree, these are usually for support.

When you repot a tree it can be very unstable in the pot until the roots grow and establish themselves again. After a repot the shallow roots are not gripping the soil and the tree can easily be knocked or blown over and the stones (or rocks) just stop this from happening and hold the tree into position.

The stones support the trees by adding enough pressure to the soil to stop it and the roots from moving. They also can be leant up against the trunk, which will also keep this in position too; usually it’s a bit of both.

The stones are only temporary and are used instead of wire. Its ugly, but it does the job. It’s very simple to do and requires no skill, tools or purchases, you just need to pick up some stones from the garden and that’s it.

I’ve had trees fly away in the wind or be knocked over by animals, which is my own fault for not wiring the trees into the pot, but rocks can usually save the day in these situations and will keep the tree in place until the roots grow into the new soil.  

Should You Wire A Tree In To A Pot Or Use Stones

You are probably now wondering what is the better technique, stones or wiring?

Wiring is of course the more traditional and more commonly method for securing a tree into a pot and to be honest it is the better option.

It is a little harder to do and there is the risk that the wire could damage your roots, but in general it is the best way to secure a tree into a pot and make sure it doesn’t move around.

The annoying thing about wire is that it can sometimes make it difficult to get a tree out of the pot when you need to repot, but really so long as you can access the wire from the underside of the pot, you can quickly cut it and free the tree.

Its maybe a little more complicated than simply placing stones on top, but if you can, wire your trees in, it is the better method.

Using Large Stones For Aesthetics 

If you wanted to use a stone in your bonsai pot for aesthetic reasons, you could. It’s not really seen in traditional Japanese bonsai, but you can do what you want. If you feel it looks nice then go for it.

There is nothing stopping you from placing a stone in your pot and enjoying how it visually interacts with the tree.  

Having Separate Stones In A Bonsai Display

A more common approach is to have a stone separate from your tree, as part of an over all display.

These are called Suiseki (somtimes called viewing stones) and are totally their own hobby, but are very closely tied to bonsai. You will see them either displayed on their own or beside bonsai, usually in shows.

Usually they have a custom fit wooden stand made for them or they can actually be displayed in very shallow bonsai pots, which looks pretty cool.

I really like suiseki and I think more western bonsai fans need to get into this whole side of things. It is a lot more interesting than just “rock collecting”, which it is often mistaken for.

Using Gravel For Aesthetics

I think it is quite common for people to put a layer of gravel/ small stones on their bonsai pots. This is not really seen often in traditional Japanese bonsai, but elsewhere in the world you will see it. 

This can look nice, but it has no real purpose other than its looks.

You could argue that this layer of stones could affect the watering, but probably not. Enough people do this that if it was a problem, we would have known by now. If anything I think having a top layer of small stones might actually allow the layer of soil underneath to dry more slowly, as it’s not in direct light.

I also think this layer of stones may allow for roots to grow in the soil, right below this layer. I have not tried this myself, but I know when I place larger stones and lift them up, there will be roots directly under the stone. This is also how moss works, where it acts a top layer that allows roots to grow directly under it.

If you are going to do this, I would suggest you use to use lava rock or akadama as I think this will look the best, but you could really use any sort of gravel. I’m not a fan of the bright coloured stones, like aquarium pebbles, but if you like them, go for it.  

Glued On Gravel Is An Issue

Some shops will sell bonsai that have gravel glued on to the pot. If you find this, remove this at once.

Having the gravel glued on like this is bad for the tree as it will stop water getting through and down in to the soil. The glue fills the gaps, blocking the water from entering the soil, so it is very different than using loose gravel.

You will find this technique being used on cheap bonsai that are being sold in places that shouldn’t really be selling them, like the supermarket. They are being sold as more of a gimmick than a real tree, they just want it to look nice so you buy it and they are not really worried if the tree dies on you within a week.

If you get a tree like this, you need to address this issue fast as it is a serious health risk.

Root Over Rock Bonsai

If we are going to talk about stones in pots, then we need to at least mention root over rock bonsai, which is more when the stone becomes a part of the planting itself.

For this you need a big stone, basically a rock. You then plant the tree on top of the rock and drape the roots down and over it, so that the tree is now growing over the rock.

You initially have to cover this all up, but over time you can expose more roots and the rock and end up with the tree on top of the rock, with roots gripping the stone and going down it and into the soil.

It kind of makes the tree look like its growing on a cliff edge and is a very cool effect.

Conclusion

As you can see there are a number of ways stones can be used with bonsai. They can be used for both support and aesthetics and are not actually necessary, you can easily support a tree with wire and use other things for aesthetics, like moss, but the option is there for you if you want to use them, they will do what is required.

(You can read more about – Should You Put Moss On A Bonsai?)