What Do Healthy Bonsai Roots Look Like?

When you are growing bonsai trees, the roots are a very important part of the tree. It is also vital that you know what condition your roots are in so you can work out what type of work you can do and so you can keep the tree healthy.

The roots are like the engine of the tree and if they are not working properly your tree will die.

In general there are two things we want from bonsai roots, we want them to be in good health and we want them to look aesthetically pleasing. If you can achieve these two things, you will end up with a good tree.

The Health Of Your Roots Is The Most Important

If you have healthy roots, you have a healthy tree. A lot of problems people have with their tree usually come from a problem with the roots.

Knowing what healthy roots look like is important, mainly so you can spot when they might not be doing so well and try and correct the problem. You will only really get a good look at your roots when you are repotting, so this is when you will really get to evaluate how they are doing.

Bonsai Roots Should Not Smell

Before you even look at your roots, you will know there is a problem if you can smell them. You don’t even need to take the tree out of the pot, you can just get close and give them a sniff.

Healthy roots should smell neutral. Maybe a little earthy, but it’s kind of nice smell. Some trees smell very distinct, but also in a nice way. For example lemons tree roots, smell like lemon.

If you get close to the pot and wince in disgust. Something is wrong. If your tree smells like stagnant water, or just a general rotting smell, this is not good.

You probably have something wrong with your roots and it is most likely that they are too wet and starting to rot. You need to deal with this or it will only get worse and the tree will die.

(You can read more about – Root Rot In Bonsai (What Is It? and How To Fix It))

The Colour Of Your Roots Can Tell You If There Is A Problem

The colour of your roots is also a good indicator of the trees health. It’s hard to say exactly what colour they should be, as it’s species dependent. Very tree will have slightly different coloured roots, but you can usually tell if something doesn’t look right.

Most roots are a sort of yellowish white colour but you can get red and browns and all things in between.

You will also find that most trees that are actively growing will usually have white tips at the end of the roots. As theses new tips harden off they will change to the colour of the rest of the roots. If you do not see these white tips it does not always mean the tree is in trouble. It just might mean it may not be growing at that exact time.

You will not see these white growing tips when you are repotting, as you want to be repotting just before they starting growing after winter. If you do see them, it means your tree is actively growing and it’s probably not the best time to repot.  

If you look at the roots and they are black, this is generally a sign of trouble. Some roots can be very dark, so that is okay, but very black along with the foul smell usually means your roots are not healthy.

Roots Should Not Be Dry

This is slightly harder to evaluate, because if you have just watered, your roots are going to be pretty wet. However, you should have a good idea when you lasted watered and should be able to work out if what you are looking at makes sense.

If you roots are looking extremely dry, to the point they are crispy, this isn’t good. You can try and soak the tree in water, but depending on the species it may be dead. Most trees do not really like to become bone dry. You will find the soil dies out and then shortly after the roots will dry out to. So if you have crispy roots, they have probably fully dried out and been this way for a while, so are dead.

Although you will probably know if this is has happened from how the top of the tree looks.

If your roots are too wet, this can also be normal at times, but if they are so wet they are starting to feel slimy, this is bad. This is the start of root rot and if your roots do not already smell bad, they will be soon.

A healthy roots system just needs to be damp. So it will not be too wet and will not be too dry. If you can keep them like this, they will be happy. 

Bonsai Root Aesthetics

How the roots look is important for bonsai, but the health always comes first. The tree can look beautiful, but if it’s dead, well, that makes everything a bit pointless.

Getting your roots to look aesthetically pleasing is something you need to work on over time by repotting and pruning the roots regularly and slowly getting them to look how you want, while also keeping them healthy. 

(You can read more information on Developing A Nebari (Spreading Roots))

Radial Roots

You want your roots to come from all around the trunk, the full 365°. If you imagine looking down on your tree from above, you want your tree to be like a bicycle wheel, where your trunk is right in the middle of the wheel, and then all the roots will be coming out every direction like the spokes.

If you look at a tree in nature, they have roots like this.  

One Plane for Root Flare

This can often confuse people, but once you get a tree in your hand, you will understand. You will find that roots grow at different levels along the trunk.

Your aim is to reduce this, so there is only one level and you end up with all the roots coming from the same plane. When you do this, along with having them come out from 365° you will end up with a very good root system.

This does a few things. It firstly makes the roots flat and shallow, so they can actually fit into a bonsai pot. It also allows us to develop a very nice root flare. As all the roots thicken over time, they all swell and make the trunk very thick in that area.

This can happen with the branches when more than one branch grows in an area and it always looks bad as the taper of the trunk becomes strange.

However, we can use this to our advantage with the roots. Since everything is one plane, and of course there is nothing below, we can allow this area to thicken, and then become wider than everything above, which is actually good taper! This is how you get a great trunk flare.

Root Divisions

Once we have roots growing from where we want, we then need them to spread out form the trunk, but we need them to divide like how we want the branches to. We want lots of divisions and ramification. If you have a couple of long straight roots coming out of the trunk and then dividing far from the trunk, it does not looks as good as a tree that has roots that divide close to the trunk.

This looks even better when the roots go from thick to thin, again just like how the branches should be growing on the top of the tree. 

Conclusion

Hopefully now you can identify if your roots are healthy and if they are becomes aesthetically pleasing.

If you can keep them healthy, the aesthetics will come with time. It’s a slow process but it will happen.