Nebari is the Japanese word meaning the lowest part of the trunk and the visible part of the roots. In Japanese bonsai good nebari is deemed a very important aspect of the tree. A trunk that flares out on all sides into a strong root system is aesthetically pleasing and gives the impression of great age and stability. In nature, old trees regularly show this flaring buttress and strong supporting roots. As they age and thicken, roots that were hidden just below the surface begin to show above the surface of the soil. A tree that has a strong network of roots around the trunk will eventually end up with a fused mass of wood as roots thicken and fuse together. In contrast trees with one sided or weak roots are likely to be blown over during storms and so do not live into old age. It is not surprising that bonsai growers attempt to reproduce this buttress trunk and strong root system in their trees to give the impression of age and stability. Outstanding nebari is not often seen in trees in nature here in southern Australia. With the exception of a few rainforest species like Moreton bay Fig our native trees do not seem to produce a spreading mat of surface roots like many of the exotic species. This raises the question as to whether developing great nebari on Australian native trees as bonsai should be as important as it is in the Japanese styles of bonsai? Our plantings of exotic trees are also relatively young, mostly less than 200 years, but you can sometimes get a hint of how older trees develop when walking through some of the older suburbs and parks. Take particular note of Plane trees and English elms as these have been extensively planted and seem to produce surface roots and impressive nebari at a relatively young age. I have even seen street trees where the roots have merged to produce a solid plate of wood around the base of the tree. When you do see such a tree it is immediately obvious that it is both old and well anchored and you can see why bonsai growers value good nebari so highly. As with most aspects of bonsai, nebari can be influenced with the right techniques and growing conditions. Correct rootpruning of young stock helps to produce more lateral roots that are the basis for future nebari. When repotting and root pruning, roots that are growing downward under the trunk should be cut back very short or removed entirely. This forces the tree to rely more on the radial surface roots and they will thicken and develop accordingly. As these radial roots develop the base of the trunk is inclined to thicken and flare out as well giving the tree a solid looking buttress. Radial roots should also be shortened considerably when pruning the roots of young bonsai stock. Like branches, when a root is cut it produces a number of new root tips from near the cut and so, like branches above, the more often the roots are cut back, the better ramified the root system will be. If you can encourage a great number of roots close to the trunk of a young tree these will grow and thicken until they begin to merge into the much desired spreading root system or even, in time, a solid plate of fused roots. Over many years of growing bonsai and trying different techniques we have realised that the early stages of developing bonsai are critical in producing the best nebari on the future tree. Rather than using trees mass produced for the general garden trade we grow our trees specifically for bonsai right from the start. All our starters have the roots cut and arranged every time they are repotted to give the best possible start to the nebari of your dreams.

2 thoughts on “Nebari

    • Your assumption is correct Maggie but does depend on species. Some trees develop good surface roots very quickly and easily but others do not. I have seen many articles in bonsai magazines dealing with replacing or improving rots on collected trees.
      Even with the best techniques some trees will still produce less than desirable nebari but the success rate will be far better than just leaving the roots to grow as they wish.

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