Trees often get forgotten in the winter but there are many advantages to having them pruned in the winter. When the leaves have fallen the structure and direction of the growth of a tree is much easier to see and work on.
Certain diseases such as black knot, are best controlled in winter because the symptomatic branches are much easier to spot and remove. Diseases are also less likely to spread to other trees or through fresh pruning cuts during the dormant period.
Insects are also dormant in the winter which is why Elm trees can only be pruned between October 1st and March 31st in Calgary and all of Alberta. This is to prevent the spread of Dutch Elm Disease which is carried by elm bark beetles that are attracted to fresh cuts and deadwood of Elm trees. If you have a fragile landscape you can take advantage of the frozen ground to protect any potential impact on soft or delicate areas below the tree being pruned or removed.
Summer has so much to offer and so little time to give, so why not take advantage of the fact that you can work on trees and shrubs in the winter and save some of that precious summer time.
You may want to consider giving the shrub a fresh start often referred to as either rejuvenation or coppicing. The practice of coppicing involves the cutting of stems within a few inches from the ground to encourage regrowth from the basal stems and roots.
One of the major advantages of rejuvenation is that a healthy shrub with a healthy root system will grow back robustly and surprisingly fast, at this point you can retrain the shrub for desired appearance and shape. Most deciduous shrub species in the Calgary area respond well to being coppiced. For serious pest infestations such as oystershell scale on cotoneaster shrubs and hedges rejuvenation pruning is the only viable option for recovery. The most ideal time to coppice or rejuvenate a shrub is during the dormant period, this is also a great time to get rid of years worth of accumulated debris in really dense shrubs.
People often ask how we are able to prune dead branches in the winter when there are no leaves on the tree and the whole tree looks dead. With a trained and experienced eye there are four clear indicators to look for when determining if a branch is alive or not.
1 Look for buds, if a branch or twig has buds this is a clear indicator that the branch may be alive.
2 Colour can also be used to make the difference between a dead and live branch, the dead growth will be either lighter or darker in colour depending on the species and how long the branch has been dead for.
3 Check for bark texture, a live branch should have a plump and full appearance and the bark will be firmly attached to the wood. Branches that are dead or dying will have more of a shrivelled look from the absence of water in the bark and branches that have been dead a long time can also be absent of bark.
4 Flexibility is the final method we used is the first 3 still have not helped in providing a definite answer of whether the branch is dead or not, using a light flex as a test, a live branch will be pliable and remain intact and a dead branch will either break or not bend as easily because dry and dead wood does not have the same bending properties as live healthy wood.
Finally a bonus test is the temperature of a branch, we don’t really rely on this one because we prefer to keep our gloves on our hands in the winter. Dead and dry branches will be warmer to the touch than healthy live branches which have a degree of moisture content making them feel cooler.