The tree featured in this article is a Berberis thunbergii, more commonly known as Berberis or Barberry. It is often found growing in gardens and areas of landscaping and is a dense, rounded, deciduous shrub with small oval leaves to just 3cm long. It is often remembered for its many needle-sharp spines that cover its branches, making collection and pruning painful unless you are careful. Beware, the spines will easily penetrate most work gloves!
Though very slow to thicken and develop from nursery stock, old stumps are relatively easy to find in gardens and these make ideal bonsai. Berberis are easy to collect having shallow fibrous rootballs, they backbud well and are very vigorous makign branch development quick. The main drawback with Berberis is they that callus very poorly (if at all), so large wounds resulting from removal of (the often numerous) suckers and unwanted trunks will not heal over. They must be dressed and included as part of the final design as will be seen on the bonsai featured in this Progression Series.
This Berberis was an unwanted shrub dug up from a neighbours garden during August 2005. Ideally you should collect Berberis in the Spring before the leaves appear but this stump had to be removed immediately to make way for building work.
The stump is seen in the image above, immediately after collection having been chopped back severely and planted into 100% inorganic soil. It has been 75% bare-rooted to rid the tree of as much ground-soil as I could without disturbing all of the rootball during the growing season.
From a different angle (that will eventually become the back of the bonsai).
November 2005: 3 months later and the tree is still in leaf, it was late to drop its leaves for the Winter (it is not unusual for severely shocked trees to ignore changes of season). The Berberis had recovered well despite being chopped and collected in August and produced many vigorous new shoots.
At this point I was still trying to work out a final design for the tree as a bonsai. My immediate thought at the time of collection had been to style it in a multi-trunk/clump form but on closer inspection, I knew this would never look particularly good; the trunks lacked taper, movement and were poorly placed.
Again, the Berberis as seen from behind
So in February 2006, with the tree finally out of leaf, I decided to chop all but one of the trunks so that I could develop the tree as a single-trunk bonsai. I selected the best lower trunk I could find and the remaining trunks were removed. The trunk-stubs were left in place for carving in the future.
June 2006: by midsummer the tree had grown very strongly and I had needed to prune it back and thin out numerous shoots and suckers a number of times. There are few tree or shrub species that grow this vigorously in the UK, particularly less than a year after collection!
Determined by the shape and taper of the trunk, the nebari (surface roots) and the possibility of 'hiding' the scars (from the front view at least), the image above shows the front view that I determined to be the best and the one I would base the design around.
A few hours later and the old trunk stubs have been carved closer to the trunk, surplus shoots removed and the new main branch guy-wired downwards (guy wires are often easier to use than coiled wire on brittle wood such as that of Berberis)
As can be seen above, one peculiar feature of Berberis is the yellow wood!
December 2006: 6 months later and the new shoots that have grown since the tree's last pruning have been pruned and wired.
August 2007: After several months of strong growth, the foliage had begun to fill out well and the tree had required repeated pruning to keep it's shape. The tree has started to begin to look like a bonsai in just 2 years.
April 2008: During the Winter I carved the large trunk wounds further, turning them into dead wood hollows (uro) and sealed the wood with wood hardener to ensure it did not rot in the future.
In March the bonsai was finally potted up into a large 13" diameter bonsai pot by Erin Bonsai, made with a finish that compliments the mature bark of the tree .
June 2008: Berberis has a vivid green leaf during the summer that is followed by...
.......strong yellow and red Autumn colours. (October 2008)
Close up of the root jin; the individual colours and texture of the bonsai pot can also be seen
Height of bonsai: 20"/49cm, 6"/15cm trunk diameter