Spruce bonsai are beautiful at any time of year, but in the spring they brighten with masses of light green buds. Here is an Engelmann Spruce that illustrates why we pinch these buds in spring.
The Engelmann Spruce growth habit is loose. If we were to just let this spruce grow, the looseness would be perpetuated year after year, and we would be unable to create dense masses of foliage. Which allow us to create shape in our trees.
The image above is our example Engelmann growing naturally, without pinching, and before styling.
Spruce buds elongate in mid-spring.
When half out—an extending shoot but not fully out and hardened—take the tip with the fleshy part of the fingers and bend upwards, snapping it off. If it’s a little hardened off you may need to hold the base of the shoot so the whole thing doesn’t come off. When you time it right, it’s one of the most pleasant tasks in the bonsai garden. Put on some good tunes and pinch.
Pinch just the strong ones. A few days later you may find the smaller buds are elongating well, so pinch those now. In about 3 weeks all the shoots have finished extending. (To the right is a shoot pinched the year before.)
With pinching, we gain density.
Buds rarely form on the shoot that we pinch, but form back on the older shoots and junctions. These push the following year, filling in spaces. Then we can cut away those we don’t want in the fall.
If you have a healthy, strong spruce, perhaps try pinching to clarify the foliage pads. Because pinching slows down the tree it is best to wait until the tree is styled before beginning to pinch.