The Cotinus shrub, also known as smoke bush, provides a colourful addition to any landscape. The flowers--which range in colour from blue to smoky yellow and orange--bloom in the spring, but the famous purple foliage lasts all year round. Its versatility allows it to be grown as either a tree or a shrub.
The American Cotinus shrub is native to southern states, such as Tennessee or Texas, and is tolerant of drought conditions. Pruning is an important part of maintaining any landscape, as long as essential plant parts are not removed or reduced.
Determine whether pruning is necessary. The size and denseness of the shrub are one indication. This is an especially important decision when working with the Cotinus shrub. Left alone, it will grow to tree size and a dense shrub will not get good sun to the centre of the plant. A good guideline is if you can't see any portion of the centre, the scrub is too dense. Inspect the shrub for signs of disease. Look for cankers, which are areas that look like burns.
Using the pruning shears, remove all dead or broken branches and any that appear diseased. Specifically, cut away any branches with cankers. Cankers are a sign of infection and must be removed to avoid spread of the illness. When cutting branches or shoots, try to cut at the origin, where it starts growing, or down to the next strongest branch, this will help maintain a robust, strong shrub.
Using the shears, cut away the lateral stems, ones growing to one side, on the main branches. Since this shrub is not one you shape in a formal way, like an evergreen, let it follow a natural growing pattern. Remove wayward branches or ones that cross over another. This will allow sunlight to reach the centre of your shrub.
Cut away branches that are growing over a sidewalk or hitting against a building, this will reduce the size of the shrub and make it a good fit as a border.
Make heading cuts. Heading cuts help you manipulate the pattern in which your shrub will continue to grow. The bud on the branch closest to your cut will determine the direction of growth. When you are looking at a branch, look for a bud facing out from the centre of the bush as opposed to one pointed left or right. This will prevent wayward and cross over branches from growing.
Make your cuts about 1/4 inch above the bud and cut at an angle. It's best not to cut more than a couple of buds in. Do this annually in the spring. You can also put on your gloves and pinch off any buds on the left and right of the stems below your cut. This will help the shrub grow less dense for the next season. Just pinch off two or three buds. Don't remove buds closer to the centre. This will stimulate healthy growth.
If you wish to take full advantage of the deep colours in the Cotinus shrub, every spring, cut it back to within a foot of the ground. This will spark immediate growth of lush wine red and dark purples. You will not get any flowers for that year, however. Clean and oil your pruning shears. Wipe an oily cloth on the blades and sharpen if needed using an oil stone.
This shrub resists pruning. It will often grow gangly stems. If this happens, it's best to cut in down to the ground and allow it to re-grow. This is stooling the shrub.