Bonsai is the art of growing a tree in a pot with the aim of creating a miniature ancient  image. The three essential components being the tree, the bonsai pot and the medium it is planted in. These next few article will be about understanding the anatomy of a tree. This first part will focus on the roots.

Tree Roots

Anatomy of a tree - wild fig tree roots
Fig tree roots visible from above the ground.

The foundation of any tree are its roots. In nature the roots can generally grow uninhibited and this will be reflected above the ground; if roots are free flowing the top will likely be free flowing but if the roots have many obstacles like rocks, the top will likely reflect that in its appearance.

Trees need to constantly grow to survive, so if the roots are stopped from growing this will mean the eventual demise of the tree. In bonsai we grow our trees in pots which does restrict the growth of the roots, this is why repotting and giving the roots a trim is essential to their health. This restriction in space is what keeps them smaller than there in ground counterparts.

The roots also provide the tree with nutrients that are carried up in water. These nutrients being essential to the tree’s health. The roots have a capillary structure that continuously bring this water up from the soil into the above ground tree structure. This is also the case with bonsai trees however there is more responsibility on the carer to ensure that they are watered and also fed with fertilizer through out the year. The season and the climate dictating when these need to be carried out.

In nature the roots also anchor the tree in the soil. This is not the case when you have a tree growing in a pot, especially a shallow one (however we want to create the image that these surface roots do anchor the tree). Wire must be used to anchor the tree into the pot and this is usually done by using the drainage holes and wiring the tree into place when repotting is carried out. This technique stops the tree moving and aids us especially when we are styling and maintaining the tree.

In bonsai we use the term ‘Nebari’ to describe the visible surface roots. These are important to the tree’s image and help create a sense of stability. This root flare is an important element to look for when buying a tree but there are techniques that can help improve this over time.

Anatomy of a tree - nebari
Example of impressive root flare (nebari) on a bonsai. Amur Maple. © Jerry Norbury