Earlier this summer, I pruned and defoliated two field grown trident maples. I reduced all of the branches on one of the trees, and left a sacrifice branch on the other.
Both trees have grown vigorously since they were pruned, but they produced growth in different areas.
The tree with the sacrifice branch produced a small amount of low growth, but invested most of its resources to extend the sacrifice branch which is now over eight feet long.

Trident maple after cutback and defoliation – July, 2020

New shoots on the lower branches eight weeks later
I reduced all of the branches on the second tree, and as a result, it produced more vigorous growth along the trunk.

After cutback and defoliation in July

New shoots on the trunk eight weeks later
Knowing how trees respond in these two cases helps us determine whether or not we’re better off keeping or removing sacrifice branches.
If the goal is to thicken or extend the trunk, heal large wounds, or strengthen the roots, I’ll leaving sacrifice branches alone. If the goal is to encourage as much new growth as possible on the branches that will form the future silhouette, I’ll reduce sacrifice branches.
In the case of the trident maples above, I’ll let the trees grow freely until the leaves start to turn color at which point I’ll prune and wire the branches in preparation for next year’s growth.
New Resource: How to grow bonsai from seed or cutting
For those interested in growing bonsai from scratch, I’ve created an easy-to-follow overview of the process to help get you started.
The guide, “How to grow bonsai from seed or cutting,” identifies development goals for each stage of development to help you avoid common pitfalls.
I wrote the guide for people who are interested in investing the time and energy required to create quality bonsai. You can read the guide now at the link below: