With the semi-cascade bonsai style (or han-kengai), the trunk and crown of the tree are trained downwards over the side of the container. The style is (as you might guess) similar to the cascade style, but a less extreme version where the crown does not go below the bottom of the pot.
This classic style of bonsai is very attractive and popular, and easier to achieve than a full cascade.
Form
The form of the semi-cascade style or han-kengai is similar to the form of the cascade bonsai style. The trunk and the crown grow outside the confines of the container and over the side of the pot, just as with cascade style, however they do not dip below the level of the container or pot base.
The trunk of the semi-cascade often does not bend more than 45 degrees below the horizontal level base of the container in which it resides.
An issue with this style is that it is not very well defined, and there are disagreements between some bonsai artists on the finer points of this style.
Many bonsai practitioners consider that the semi-cascade style should not go below the ‘ground level’ and if you look at the creations of many semi-cascades, many do not even drop below the upper top of the container.
However, one camp of bonsai artists consider that the semi-cascade style can be allowed to project below the container’s ‘ground level’.
The important thing in the semi-cascade is that the tip or apex of the bonsai tree should always stay somewhere between the top rim of the container and the base of the container. As long as it lies within this zone, it can be classified as a semi-cascade.
How to style a semi-cascade bonsai
Styling a semi-cascade bonsai tree is a similar process to styling a cascade bonsai tree. You will need a deep, heavy container or pot to ensure it stays stable as the tree grows, and the bonsai tree should be planted close to the center.
Extensive use of wiring will be required to shape the trunk initially, though a lesser amount is required as compared with shaping a full cascade tree.
Best trees for semi-cascade bonsai style
The choice of species to use is important as well, and Junipers are considered the most suitable species for the semi-cascade, as are flowering cherry trees like the Japanese Sakura, which will produce a nice blossom spectacle in springtime. Weeping willows and chrysanthemums also make good choices for the semi-cascade style.