Allen Wilson is a Vancouver gardening specialist. Email Allen Wilson at firstname.lastname@example.org.
In a recent article you mentioned that it was important to get an early start on tree and shrub pruning to avoid later problems. Most of our trees and shrubs were planted three years ago. They have made some nice growth the last two years. What should I be looking for?
Most shade and evergreen trees should have a single dominant central trunk. Sometimes one or more side branches will grow almost as large as the central trunk. These extra strong branches should be shortened to about a foot.
If the top of the central trunk becomes damaged or broken, the strongest side branch should be trained to replace it and other side branches shortened or removed. Any side branches that grow straight up should be removed.
As trees make some growth in height, there is a tendency to remove lower side branches below 6 to 8 feet. If these branches are shortened, but left on for an extra three or four years, they will feed the central trunk so it will grow thicker and stronger. The trunk will also grow taller at a faster rate.
A 6-foot circle should be maintained with no weed or grass growth. This circle can be enlarged as the tree grows. Plants growing in this area compete for water and nutrients, which slows the growth rate of the tree.
This area can be easily maintained by keeping a layer of bark dust or other mulch. Most weed seeds need light to sprout. A 2-inch mulch will prevent 90 percent of weed germination. Steel or plastic edging will keep the grass from growing in.
Avoid using power clippers on shrubs unless you want hedge-like boxes and balls.
In the early stages of growth there will likely be only a few long upper branches to be shortened to avoid shading the lower branches.
Taper your pruning so the lower branches are the longest and the upper branches are the shortest. Try to make pruning cuts so they are slightly shorter than surrounding growth.
If shrubs are obviously outgrowing the location where they were planted, why not move them and replace them with smaller ones? Plants recover best if they are transplanted before they start spring growth.