Cutback – Korean hornbeam

An important theme in bonsai: to develop or  maintain a tree of a given size, we need healthy interior shoots. Without interior shoots, we have few options during cutback.

Now that the sun is appearing with some regularity in Northern California – and some timidity as it’s still cool – bonsai are beginning to grow quickly. Of my deciduous trees, my Korean hornbeam is the most vigorous. Strong areas already have 8-12 new leaves. These vigorous shoots are great signs of health, but they also shade out interior branches. Time for cutback.

Korean Hornbeam – May, 2011

I typically cut back to three or four leaves – two leaves in particularly vigorous areas.

A vigorous shoot

Vigorous shoot reduced to two leaves

Moderately vigorous shoot

Shoot reduced to two leaves

I ran out of time about halfway through the cutback, so I took the tree home to finish the work. Are workshops ever long enough?

Cutback half-way complete

This past weekend I finished the cutback.

Cutback complete

You may notice that some of the leaves have browned a bit at the edges. This was a result of exposing new leaves to the sun on some of the first warm days of the year. No matter – I don’t expect these leaves to stick around long. After completing the cutback I noticed the tree was still full so I began thinning additional foliage and removed the droopy leaves you see hanging down. I may yet trim the leaves to let in even more light as I’m very interested in improving the interior ramification of the tree. Hornbeam are completely defoliated, on occasion, in Japan, but I don’t know that my tree could withstand this work. In lieu of more drastic technique, I’ll opt for leaf cutting and minor cutback.