Nebari – The Root of the Matter


These roots have grown over time, dropping of the side of a cliff.

No, we are not talking about the Nebari fictional alien race from the planet Farscape, but the Japanese term generally used to indicate the roots and specifically the root flare at the bottom of the trunk where the root region starts. It also indicates the visible surface roots.

Wikipedia refers to it as: “Also known as “buttressing”, nebari is the visible spread of roots above the growing medium at the base of a bonsai. Nebari help a bonsai seem grounded and well-anchored and make it look mature, akin to a full-sized tree.”


My idea is to write three or so Blogs focusing on Nebari and the development of roots. There is no doubt in any Bonsai artist’s mind that the roots of a plant is where it all starts. Healthy roots = healthy plant (generally). A plant absorbs most of its water and nutrients from the soil through the roots. We therefore have to know something about soil and its water retention and draining properties. Not all soils are created equally. We also need to know something about the physiology and anatomy of roots. This knowledge will help us to understand many of the concepts around root pruning. This will come in later Blogs.

Autumn bonsai images 2014 (17)

A tree growing in a woodland area. These roots definitely add to the character of the tree and indicate that it has been there for a while.

Getting back to the Nebari, the main aim of establishing a root flair at the base of a tree is to indicate age. A wider base caused by a flaring just above the roots, helps to establish the taper of a tree. One way to develop taper is to increase the circumference of the tree at the base and to keep the top of the tree relatively thin. Young trees do not have a huge flair at the base, but older trees show this without fail. In saying that, there are trees that are used for Bonsai that do not show a big root flare. Junipers come to mind here.


The roots are spread over a flat surface and tied to this surface.

There are multiple methods to improve the Nebari of a Bonsai tree. The first one is the continuous root pruning of downwards growing roots. For the health of the tree it is advised that this is done over time to enable the tree to grow new roots in the place of the removed roots. A second method is done through air layering. This is simply done through preparing the bottom of the trunk as one would for air layering and heaping up the soil or packing sphagnum moss around this area. Roots will over time establish themselves in that area. I have read about a method where a wire is bound tightly around the trunk just above the roots. The flow of nutrients will be impeded and that will cause new roots to grow from above the wire. I have not tried this method myself before and cannot comment on how successful it is. Other methods include drilling holes through flat tiles and tying the roots of the tree in a horizontal direction to the tile with wire through the drilled holes. It could also be done through grafting.

In the end, the Nebari plays a vital role in the aesthetics of the tree. It is crucial thfotolia_2553306_XSat some sort of Nebari be established as it indicates age, shows that the tree is balanced and sturdy and has been there for a long time.

The next Blog will address the science behind root development.

Liverwort and Bonsai

IMG_0035Liverworts are flat growing green plants, closely related to mosses (Bryophytes). They have no stem and only a thallus, the flat leaf-like structure that is seen above ground. They belong to group called Hepatics and belong to the Marchantiophyta, a division of bryophyte plants, the mosses. These plants are primitive, not only in structure, but also in the fact that they are old. Some sources mention that they transition onto land during the Devonian Era (400 million years ago). Goes well with Bonsai then, I hear you say. Not really.

Bonsai growers will find these plants in moist areas. Where I live we have a high rainfall in winter and I have to be very careful with watering. This is usually taken care of by ensuring that the soil medium is free draining. Most of the liverworts that I see growing on soil come from nursery sourced plants, probably because the soil contains the spores and the fact there could be lot more organic soil in nursery plant soils.IMG_0032

The problem for me is that they can rapidly cover the surface of the soil and prevent water from penetrating the soil. This is not necessarily a problem as they already indicate that the soil is too wet. This layer of Liverwort can also prevent proper air circulation through the soil. I have also had experience of Liverwort growing over moss (I want the moss), suffocating the moss to death.

IMG_0034These plants reproduce asexually and sexually. They produce bumps (cupules) on the leaves, usually during late autumn, containing “eggs” called gemmae. These produce new plants. The sexual reproduction produces spores which germinate and form new plants.

As said, these plants can be an indicator that your soil or growing medium is too wet. If this is the case, it is obvious that the medium must be changed to be more free draining. Larger inorganic particles can be used to do this. If it is still a problem, look at the top layer of the soil. This could contain spores of liverwort. Scrape the top layer off and replace with a coarse material like gravel or pea metal.IMG_0035

Harsh chemicals could be used to spray on the liverwort to kill them off, but I have found that dabbing or brushing vinegar on the leaves of the liverwort, kills them off as well.