Now is the time to prune deciduous trees. The shape, size and condition of the tree’s branches are much easier to see without leaves making it easier to decide what needs to be removed.
Prune trees to remove deadwood, broken branches, correct shapes, for safety and convenience. If a tree is too large, pruning to reduce its size will become an ongoing, yearly struggle. Sometimes, it is best to remove large trees and replace them with a smaller variety.
Always cut the branches flush to another branch or trunk allowing the tree to heal faster. Do not worry about covering wounds with pruning paint as it has been proven ineffectual.
Start pruning by removing all dead or diseased wood. Dead wood will be brittle, often with loose bark. Live wood will feel cold while deadwood will warm up when held. Diseased branches can be misshapen, have sunken areas or be discolored.
Diseased wood needs to be removed immediately regardless, of the time of year, as diseases can quickly spread to the rest of the tree or to other trees. When removing diseased branches, make sure the final cut is in healthy wood. Dipping the tools in a 10 per cent solution of bleach between cuts will keep the disease from spreading in warm or wet weather. During the winter season, diseases are dormant and tool sterilization is unnecessary.
It is important to either burn or double bag diseased wood immediately to stop the disease from spreading.
Next remove all suckers or water sprouts. Suckers are found growing from the roots around the trunk. They should be removed as soon as they appear. Water sprouts are long thin branches that grow straight upwards with out any side branches. They are the plants response to loosing too much top growth either through winterkill, or over pruning.
Look for branches that rub together as over time the bark will be damaged creating openings for insects and diseases. Remove one of the branches. Take into account the; size and health of the branches, direction they are growing and angle at which they are attached to the tree before deciding which one to cut. As the ultimate goal is to have an attractive plant, be sure the branches that are removed will not make the plant misshapen. Never keep a branch that appears to be weak or diseased.
Branches that can be hazardous or rub on buildings are next on the list. Take aesthetics into account when removing bottom branches to make mowing easier.
Lastly, shape the plant.
Never remove more than a quarter of the plant in one year. Removing more will result in a profusion of new watersprouts that will need removed next year. Better results are achieved by spreading massive pruning projects over a number of years.
Anyone can prune successfully as long as the basic rules are followed. Remember, removing less is better than too much.
Linda Tomlinson is a central Alberta horticulturalist. She can be reached at firstname.lastname@example.org.