I’ve been fortunate to have the chance to study many world-class trees in Japan and the US, giving me the opportunity to think about how they were made. When it comes to making great juniper bonsai out of yamadori material there are a few tricks and complications that can force compromise when you really get into transforming a piece of stock into a bonsai.
With juniper, the lifeline and deadwood are attached, integral. But, one is needed and the other is not. One solution is to split the live wood from the deadwood in key places which makes bending easier, or even possible in many cases.
Grafting is the obvious alternative to large bends. Rather than move foliage from one place to another you simply add the foliage where you want it and grow it into shape. This also has the advantage of allowing you to change the foliage to the type that grows best in your climate. But, while this may seem like the perfect solution, it is frequently quite limited. When a tree already has a complete and mature crown the prospect of grafting to simply lower the crown a couple inches is absurd, bending is the obvious answer because it maintains the years worth of fine branch growth.
In other cases a tree may have multiple lifelines at the base that split and move into the foliage in challenging ways. Reducing a mass of foliage may lead to a part of the lifeline at the base being killed when it is integral to the design. Splitting and/or grafting can solve this problem. The tree below was grafted along three lifelines, for a tree this size (about 24″ tall) it can take many years for the grafts to grow out to create a canopy that is in scale with the trunk.
Bonsai is frequently about compromises. Whether you split a lifeline to move older branching into a better position, or graft foliage back to create a new branch you are moving material toward a better and more refined result. Consider both techniques carefully, and use them to make your trees better.