How To Develop A Chojubai-

Last week I was flipping back and forth between old photos and newer ones to see how a Dwarf Flowering Quince ‘Chojubai’ bonsai has changed.

Just to take six years in the life of this old fella, from 2012 to 2018, one can see a difference in the ramification. The first photo looks uninspiring, old and good bones but little else. By the second photo we begin to see the results of the last few years, and the reason why one trims deciduous bonsai.

• A deciduous bonsai won’t generally ramify well on its own. It will simply lengthen its branches and kill off the inner twigging, which we want to keep. Timely trimming is necessary to keep what the tree already has, and to build further ramification.
• However if the tree is a shrub, like Chojubai, the situation has an added complication in that it is a basally dominant plant. So if we don’t trim the basal shoots and those arising on the trunk, the old, twiggy, exterior parts of the tree will weaken and eventually die. 

Each species has its own ramification technique. For a Chojubai the technique is trimming back the extended shoot about the time it’s hardening off in late spring / early summer. Leave about 1/3″ / 0.5 cm of the shoot, which will have several buds. From that area 1-3 shoots might arise, but usually just one. But back budding can occur as well. If you do this early enough, in June, you might also get a summer trim in, late July, and then a third and final trim in the fall which won’t create regrowth.

Dwarf Flowering Quince ‘Chojubai’ in 2012, showing good bones but little else.

Same Chojubai in 2018, six years later, with ramification created from trimming back extensions in late spring. The directionality of the branches was created by careful trimming and not wiring. If you trim fast without looking where the bud is pointing, you will create a mess and might as well wire your tree.

Also 2018, but taken in late summer when half the leaves fall off, and, as is customary for Chojubai, when another burst of flowers comes out.

Like many plants—fruiting trees, like apple, and some conifers such as larch and gingko—there are two shoot structures. Whorl-type growth has leaves that are very closely set in a circular pattern, often called a spur branch, and the other structure is an elongating shoot. On a Chojubai trimming of the shoot at the right time can trigger some of the spur branches to change into an elongating shoot. It is this extension growth that will allow you to create branch structure, and thus ramification. The spur branches will create a bit of twigginess.

Trimming 2-3 times a year assumes continual fertilizing throughout the growing season, regular watering, and good sun. Chojubai can take a bit more sun than most deciduous bonsai. They flower erratically. Late winter is the major bloom time, but they can exhibit their fitful blooming potential with a late summer or fall push, too. Fertilizing consistently does increase blooming.

For more on Chojubai as bonsai, take a look at ‘Chojubai’ Quince—Diminutive Jewels.