This European Hornbeam started life as a £1 bare-root seedling in the Winter of 2000/2001. Unfortunately, I didn't take any specific images of this tree as it was just one of 50-60 similar seedling/saplings bought for growing-on that Winter. However, I have managed to find glimpses of the tree found within old pictures of my growing bed, taken over the course of 3 years.
The three images above show the tree being allowed to grow freely while in the ground in (from left to right) July 2001, December 2002 and January 2003.
While no pruning was carried out on the seedling during the early years, a wire tourniquet (for more details see this article) was applied to its base to ensure that when it was lifted from the ground, it would have the at least the beginnings of a good nebari with plenty of lateral roots around the base of the trunk.
Why was the seedling planted in the ground? In the Winter of 2000/2001 the trunk was pencil thick. Much too thin for use as bonsai of any size. Before any styling or development of the branch structure could take place, the trunk needed to be fattened up. For this reason, along with all of the other seedlings I bought that year, the hornbeam was planted into the ground and literally forgotten about for a few years. Other than the very occasional weeding around the area and some feeding with slow release fertiliser, the tree was just allowed to grow. The more it grew, the fatter the trunk would become. Any pruning would just slow the speed at which the trunk thickened up and add to the amount of time I would have to wait before the tree (and its trunk) was ready to be developed as a bonsai.
During the first two years, growth can be relatively slow and with many species, as can be seen in the images above, the trunk barely thickens. However, by the third and fourth years of unrestrained growth, most trees will be growing very strongly as had this Hornbeam. (For more details of field-growing for bonsai please see this article)
February 2005. After 4 years growth, I decided to harvest this particular Hornbeam and start the process of developing it as a bonsai. By this stage the tree had reached well over 2 metres in height and had produced a 2"/5cm trunk diameter. Using the rough guide of 6:1 (trunk height to trunk diameter) this 2" trunk would be suitable for a bonsai with a final height of approximately 12"/30cm. For a taller bonsai, the tree would have needed to be left in the ground for longer in order to fatten the trunkbase further.
The image above shows the trunkbase and the tangle of roots that were revealed after I had dug up and bare-rooted the tree to remove all ground-soil. The long strap-like roots are typical of hornbeam. First impressions weren't great but once the roots were pruned back, it was possible to tell that the wire tourniquet had produced some strong lateral roots that all emerged at the same height on the trunkbase; important for building a good quality nebari on bonsai.
After root pruning February 2005. There is a limit to how much the roots of any tree can be worked on in one sitting, so with this initial pruning I concentrated on removing the thickest, most out-of-place roots while keeping as many of the thin feeder roots intact as possible.
February 2005. Here is an image of the tree, showing the rough trunk-chop I had carried out prior to digging the tree up from the ground. The redline indicates where I envisaged chopping the trunk to a upward growing branch, but at that time (early Spring), there was no advantage in carrying out the work.
It is much better to wait until the tree has had a chance to recover and strengthen before trimming back the trunk to the redline during midsummer. At this time, healing and callusing of the relatively large wound will be strongest and fastest.
The hornbeam was finally planted into a large container using just bonsai soil and left to recover.