Q: My old-fashioned snowball bush was covered with blooms this year, but it is getting very large. How can I prune it?
A: This was a great spring for snowball bushes, which can often grow to 15 feet or more in height and width. They appear as a lovely blossom-covered (or, this year, blossom-smothered) small tree in the garden. They really shouldn't be planted or thought of as a shrub but rather as a graceful small tree.
Plant them in a sunny location where they can grow to their full splendor. They are winter hardy, the blooms appear at the ends of old wood (that means last year's growth), and they are relatively pest-free. A gardener couldn't ask for a sturdier or more reliable plant. So pruning is an easy task if you think about it carefully.
Just remember: Prune after bloom. The plant has now finished blooming, but it has not set buds for next year yet. If you prune immediately after the blooms turn brown or start to set seed, your plant will have time to grow new branches and set buds for next year's flowers. Pruning immediately after bloom time means your plant will be able to produce blooms next year.
You may need a sturdy ladder. Use a sharp lopper or a special tree handsaw. If you wish to lower the overall height of the plant, you may be able to use an electric or gas hedge trimmer. However, this shearing type of pruning will result in a very dense, clumpy, rounded and unnatural shape. It will also result in thick foliage that is unsightly and can cause fungus issues in a warm, wet year.
If you do choose to shear to reduce height, plan to prune individual branches and tips back so that you achieve an overall open and varied tip length. Avoid the ball shape, and go for a tree-like open canopy.
You could also trim from deep inside the plant by cutting close to the trunk and removing whole large branches. This technique opens up the interior for air and light and can reduce overall size. Your objective is to reduce the size by cutting branches shorter but also leaving branches of various lengths.
Stand back frequently to check your handiwork, and you should be able to prune effectively and well.
Email Pat Lea at firstname.lastname@example.org.