As with most any type of plant or tree, our Bonsais roots are always in search on new nutrient and water rich soil. And when they are inside of the container they will not be able to grow in either direction for more than a foot – depending on the size of the Bonsai container.

So we will need to prune the roots as a way to keep the Bonsai healthy.

Bonsai Trees seem to NEED fresh root growth. Regardless of how often we water them and fertilize them, if the roots reach the maximum length and size for the container, the Bonsai will lose its full and healthy look. This often results in something called chlorosis .

And pruning the roots will open up room for expansion of new roots. And for the Bonsai tree, new root growth means better nutrient absorption and better health altogether.

Here is how you can safely prune your Bonsai Tree for maximum growth and overall beauty.

There are 3 things that are considered when pruning our bonsais:

1. The species
2. The container size
3. The environment

Knowing YOUR Bonsai will help to determine when to prune , how much to prune and the best methods for doing so.

In all cases, we must sacrifice the larger roots for smaller ones. Most of the time the smaller to medium roots can be pruned with something like a Concave Branch Cutter .This is simply because smaller ones will absorb water and nutrients better -and they are newer and have more room to keep growing.

What we want to do first, is to remove our Bonsai Tree from the pot. Once removed, we must pull or stretch the roots out in a radial type pattern. This is done by taking your  Root Rake and pulling outward until all roots are separated and pulled out completely.

Bonsai plants require a substantially shallower root system than nursery plants. This means that the lower portions of the one gallon or five gallon can must be totally removed.

Very often it will not be possible to move from the nursery container to the bonsai pot in one step. In this case remove as much of the root ball as safely possible and repot to a smaller, shallower training pot. After a year or two it should be safe to further root prune and shift to the final bonsai pot.

When severe root pruning is required to get a nursery plant into a bonsai pot, I use tools such as an axe or sometimes even a chainsaw to remove the lower portion of the roots. To be on the safe side do not remove more than two thirds of the roots of a container plant if root pruning during the dormant season. Severe root pruning should only be done during dormancy. There is no substitute for experience in guiding you here. Start root pruning conservatively and only progress to more severe pruning as you gain confidence.

If the plant was in a fairly good nursery mix with coarse materials, it is not necessary to completely remove all of the old soil, although most of it should be removed. When plants are collected from native earth during the dormant season it is probably best to remove as much of the heavier material as possible to make the transition to container mixes. This heavy clay material will hold far too much water in container culture (Check out the Bonsai Soil Akadama) . It is tempting to blast the root ball with water to remove the old soil, and for some species this is perfectly acceptable, however it does cause more damage to the fine root hairs than combing out the soil.

Remove the circling roots, the thick tap root remnants under the crown and shorten larger storage roots. Try to keep as many of the fine roots as possible. The roots should be trimmed all around so that the root ball will fit into its new container with having to fold or tuck long roots into it. This is also a good time to start looking at the nebari and deciding if any of the surface roots need to be removed for aesthetic reasons. Place the root ball on a shallow pad of new soil in the pot and proceed to dibble more soil into all the spaces between the roots with a chopstick. Keep poking holes until there is a slight resistance, this means the voids have been filled with soil. Lightly tamp the soil surface and water thoroughly. This first watering should saturate and flush the soil. Water two or three times longer than you normally would to settle the soil and wash out the fine material.

You can finish by placing a layer of heavier gravel or decomposed granite on top, applying moss, or both. Then water again.

And again, pruning a Bonsai Tree can be the toughest and scariest part of growing your bonsai. And your best way to learn is by – it is very hard to explain in words how to do it. There are so many variables that are involved.

I would definitely recommend watching someone first -if thats possible.

If you do not know anyone -I think its best to get a video or at the very least a guide. There are plenty of good, cheap videos that will show you the step by step process – trust me, you will feel alot more confident and safe about the whole pruning process.

Bonsai Video Instructional Guide