Maureen Sexsmith-West Certified Arborist PR-4600A PRUNING POINTS
Understanding what is typical growth for the species and age of tree are very important when determining where and how much to cut off. This is a healthy vigorous spruce showing last year’s growth with several buds set for the next season. It can help you decide where and what needs to be pruned off and how soon it will be grow back to that point. Spruces and Pines need to be pruned to a bud or to a twig 1/3 third the size of the branch it is attached. Junipers and Cedars need can be pruned to a point where there is live tissue to take over the role of terminal.
Hard shaped evergreens are more susceptible to insects and diseases. This can be attributed to the lack of sunlight penetrating the inner portion of the canopy necessary to keep evergreens healthy. Other contributors is the introduction of internodal cuts as these can allow entry points for diseases.
Avoid removing more than 1/3 of the new growth each season or you will eventually end up with dead sticks or patches that won’t recover. There MUST be green at the end of each stem or twig. By employing a variety of pruning techniques some shrubs can remain while others are best removed. Seek advise from a qualified professional.
NEVER TOP A SPRUCE
It needs to maintain a single leader to direct moisture to the root zone and to manage snow loads. Topping usually results in competition and multiple leaders develop. Multiple leaders are subject to failure and should be evaluated. Strive to keep branches from becoming over crowded and rubbing on each other through thinning and removal of deadwood.
Selective thinning can open-up the canopy and allow some sun to penetrate into the inner part of the tree – enabling leaves to receive sunlight and remain attached longer. Candling of Pines or shaping is best achieved when the new foliage is fully extended but still flexible.
Once the branch has no live needles, it will never reproduce leaves on it.
Use extra care when working with ‘dwarf’ or altered varieties. Removal of growth regulating hormones can result in the plant adopting some of the parent growth genes as shown here.
NEEDLE SHED Spruce, pine cedar and juniper will naturally shed needles. The oldest foliage in the inside of the conifer, closest to the trunk, turns yellow or gold, then brown and eventually falls off. Shedding happens most frequently late in the season. Usually, this process goes unnoticed because it is gradual, but sometimes many needles will discolour all at once. This can be very alarming as it can look like the tree is dying. Although needle shed is a regular occurrence, keeping evergreens as healthy as possible with good watering practices, monitoring soil pH and proper pruning can lessen the amount of needles lost. Stress (drought, poorly-drained soils, improper pruning, transplant shock or insects) to the plant can cause it to drop more needles than normal throughout the season. Some diseases can result in sudden changes and needle loss as well.