Congratulations on your new home. Along with the mortgage, the neighbourhood, and the kitchen you fell in love with, you have also inherited some trees. Maybe it is a towering spruce in the backyard, a row of elms along the boulevard, or a crabapple that the previous owners planted years ago. Whether you grew up on a farm or have never owned a yard before, understanding basic tree care will protect your property, save you money, and keep your trees healthy for decades.
Get to Know Your Trees
The first step is figuring out what you have. Walk your property and take note of every tree, including the ones you might not immediately think of as your responsibility. Identify the species if you can. A quick photo search on your phone can help, or you can snap pictures and ask an arborist during a consultation. Knowing the species tells you what pests and diseases to watch for, when to prune, and what kind of maintenance each tree needs.
While you are out there, look at each tree's general condition. Are there dead branches? Mushrooms growing at the base? Cracks in the trunk? Leaves that are yellowing or spotted? These are all signs that a tree may need attention, and catching problems early is always less expensive than dealing with them later.
Watering Basics
Established trees generally take care of themselves when it comes to water, but Calgary's dry climate means supplemental watering is sometimes necessary. During extended dry spells in summer, give your trees a deep soak every two to three weeks. The key word is deep. A light sprinkle from the sprinkler does not reach tree roots, which extend well below lawn root depth. Use a soaker hose or let a regular hose trickle slowly at the drip line for 30 to 45 minutes per tree.
Newly planted trees need much more attention. Water them deeply twice a week for the first growing season, once a week in the second year, and every two weeks in the third year. After that, they should be established enough to handle normal Calgary conditions with occasional supplemental water during droughts.
Pruning: When and How Much
Regular pruning keeps your trees healthy, safe, and attractive. But timing matters. Most deciduous trees in Calgary are best pruned in late winter or early spring while still dormant, typically February through early April. This timing allows the tree to seal pruning wounds quickly once growth resumes and avoids the insect activity of warmer months.
The exception is elm trees, which must be pruned between October 1 and March 31 under Calgary's elm pruning bylaw. This regulation exists to prevent the spread of Dutch elm disease and applies to all elm trees, whether on public or private property.
For most homeowners, annual pruning should focus on removing dead, damaged, or crossing branches. This is called maintenance pruning and it reduces disease risk, improves air circulation, and prevents branch failures. Leave structural pruning, large branch removal, and crown work to a professional arborist with proper equipment and training.
Common Pests and Diseases in Calgary
Knowing the most common tree problems in Calgary helps you catch issues early. Here are the ones every homeowner should be aware of:
- Black knot: Hard, black swellings on branches of mayday, chokecherry, and plum trees. Prune out infected branches at least 15 centimetres below the knot.
- Bronze birch borer: Causes die-back starting at the top of birch trees. Thinning canopy and D-shaped exit holes in bark are warning signs.
- Aphids: Tiny insects that cluster on new growth and leave sticky honeydew on everything below. Common on lindens, elms, and poplars.
- Cytospora canker: Causes resin-soaked patches on spruce trunks and lower branch die-back. Stress from drought or poor drainage often triggers it.
- Fire blight: Causes blackened, curled branch tips on apple, crabapple, and mountain ash trees. Prune during dry weather and sterilize tools between cuts.
The Boulevard Tree Is Not Yours
This catches many new homeowners off guard. The tree between the sidewalk and the street in front of your house is almost certainly City property. You are responsible for basic care like watering during drought, but you cannot prune or remove it without City authorization. If the tree is damaged, diseased, or causing problems, contact Calgary's 311 service to request an assessment. The City handles maintenance and removal of boulevard trees at no cost to homeowners.
When to Call a Professional
Some tree care tasks are straightforward enough for a handy homeowner with a pair of hand pruners. Others absolutely require a professional. Call a certified arborist when:
- Branches need to be cut that you cannot reach from the ground
- A tree is leaning, cracking, or showing signs of structural failure
- You notice mushrooms or fungal growth at the base of a tree
- A tree has significant dead wood in the canopy
- You need a tree removed or significantly reduced in size
- Storm damage has left broken or hanging branches
- You are unsure what is wrong with a tree that looks unhealthy
Professional arborists carry insurance, use proper safety equipment, and understand tree biology in ways that prevent well-intentioned but harmful pruning. The cost of a professional service call is almost always less than the cost of fixing damage from a DIY attempt gone wrong.
Building a Relationship With Your Trees
Trees are the longest-lived elements of your landscape. The spruce in your backyard may have been there for 50 years before you moved in, and with proper care, it will still be there long after you move on. Getting to know your trees, understanding their needs, and investing in their maintenance pays dividends in property value, energy savings, and the simple pleasure of a well-treed yard. Start with the basics outlined here and build your knowledge over time. Your trees, and your property value, will thank you.