Is Your Tree Dying? Here’s How to Tell in Calgary

Most homeowners do not notice a tree is dying until it is already too far gone. That is not because they were not paying attention. It is because trees hide their problems well and the early warning signs are easy to miss if you do not know what to look for.

Catching a dying tree early matters for two reasons. First, some trees can still be saved if the problem is caught soon enough. Second, a dead or dying tree near a house or a driveway is a safety hazard that only gets worse over time. Knowing what to look for lets you deal with the problem while you still have options. If you’d like a professional opinion, Calgary Tree Works can assess your tree for you.

Here is what to check.

Start With the Bark

The bark is one of the first places to look. Healthy bark has a consistent texture and colour for that species. When something is wrong inside a tree, the bark often shows it.

Look for areas where the bark is peeling away or falling off on its own. A small amount of bark shedding is normal for some species like birch. But large sections of bark lifting or dropping off, especially when the wood underneath looks dry or discoloured, is a concern.

Cracks in the bark that run vertically down the trunk are another warning sign. In Calgary these are sometimes caused by frost cracking, which is a specific type of damage from our rapid temperature changes. A single frost crack does not necessarily mean the tree is dying, but it is worth monitoring. Multiple cracks or cracks that are spreading are a more serious signal. For more on this, see our guide on why your tree looks fine in summer but dies over winter.

Also look for soft or sunken areas in the bark. If you press lightly on the bark and it feels spongy or hollow underneath, there is likely decay in the wood beneath it.

Check for Deadwood in the Canopy

Deadwood is one of the clearest visible signs that something is wrong. Dead branches have no leaves in summer. The smaller twigs at the tips tend to be dry and brittle. The bark on dead branches often has a different colour than the living branches around them, usually a dull grey or brown rather than green or olive.

Some deadwood in a mature tree is completely normal. Trees naturally shed lower branches that are no longer getting enough light. The concern is when deadwood appears in the upper canopy where branches should be actively growing, when deadwood is increasing year over year or when more than about 25 to 30 percent of the canopy appears dead.

A tree that has lost most of its canopy over one or two seasons is in serious trouble. That kind of rapid dieback usually points to a root problem, a severe disease or a pest infestation that has progressed significantly. This is one of the reasons trees suddenly fall over with no warning.

The Scratch Test

This is the simplest test you can do yourself. Use a fingernail or a small knife to scratch a small patch of bark on a branch. If the tissue just under the bark is green and moist, that branch is alive. If it is brown, dry or shrivelled, that branch is dead.

Do this on several branches across different parts of the tree, from small outer branches working inward toward the main trunk. If the outer branches are dead but the wood near the trunk is still green, the tree may still have living tissue at its core and could potentially recover. If even the trunk tissue is brown, the tree is almost certainly dead.

This test is most useful in spring before the tree has fully leafed out. It tells you whether a tree that has not woken up yet is just slow to leaf out or has actually died over winter.

Fungal Growth at the Base

Fungi growing on or near a tree are one of the more serious warning signs. Bracket fungi, which look like shelves or fans attached to the bark and mushrooms growing at the base of the trunk both indicate that fungal decay is present in the wood.

This does not always mean the tree is about to fall down. Fungi can be present in the outer wood without having reached the structural core. But in many cases, by the time you can see fungal growth on the outside of a tree, the decay inside has already been progressing for years.

If you see fungi on a tree that is near your house or in a location where a failure would cause serious damage, that is a situation for a professional assessment rather than a wait and see approach.

Changes in Leaf Colour or Size

Leaves that are off colour, smaller than usual or dropping early are all signs that a tree is under stress.

Yellowing leaves in summer, particularly when the yellow appears between the veins while the veins themselves stay green, often indicates a nutrient deficiency or a problem with the tree’s ability to take up water and minerals. This pattern is called chlorosis and it is relatively common in Calgary’s alkaline soil, a condition documented by the Government of Alberta’s soil resources.

Early leaf drop, before the normal fall colour change, suggests the tree is under significant stress. The tree is essentially giving up on its leaves before the end of the growing season to conserve resources.

Leaves that are smaller than they used to be on the same tree over several seasons indicate a tree that is slowly declining. Compare this year’s leaves to photos from a few years ago if you have them.

Leaning

A tree that develops a noticeable lean, particularly one that has changed its lean recently, deserves immediate attention. Not all leaning trees are dangerous. Some trees have leaned for their entire life and have developed a root structure adapted to that position.

The concern is when a lean is new or getting worse. If you notice soil cracking or heaving at the base of the trunk on one side, that is a sign the root system is giving way. This is a genuine emergency situation, especially if the tree is leaning toward the house or any other structure. See our guide on what to do in the first 24 hours after a storm hits your yard if this happens suddenly.

Pests on the Trunk or Bark

In Calgary, a few specific pests cause serious tree damage that can lead to death if not caught early.

Bronze birch borer attacks birch trees and is very common in Calgary. The first sign is usually dieback starting at the top of the tree and working downward. You may also see D shaped exit holes in the bark where adult beetles have emerged. By the time dieback is obvious, the infestation is usually well established.

Ips bark beetles attack stressed or weakened spruce trees. They bore into the bark and create tunnels under it that interrupt the tree’s ability to move water and nutrients. Signs include pitch tubes on the bark, which are small blobs of resin that look like chips of dried white paint and fine boring dust at the base of the tree.

If you notice these signs, get a professional involved quickly. Beetle infestations spread and a tree that cannot be saved can become a source of beetles that move to healthy trees nearby.

What to Do When You Spot These Signs

If you are seeing one or two of these signs on a tree that is otherwise healthy looking, keep an eye on it and get an arborist out to assess it. Many problems are manageable if they are caught before they progress too far.

If you are seeing several of these signs together, particularly deadwood in the upper canopy combined with fungal growth at the base or a new lean, treat it as an urgent situation. A tree with multiple serious problems in a location where a failure would cause damage needs professional attention now rather than at the next convenient time.

Not every tree with these symptoms needs to be removed. An arborist can assess whether the tree can be treated, whether it can be made safer through pruning and cabling or whether removal is the right call. But you need the assessment to know which situation you are dealing with. See our guide on tree removal vs tree trimming, which does your property need.

The scratch test, a walk around the trunk looking at the bark and a look up into the canopy are three things any homeowner can do on their own. They take about ten minutes and they tell you whether a tree deserves a closer look. For trees near your house or in spots where a failure would be serious, doing that check once a year in spring is a reasonable habit to develop. If your check turns up something concerning, reach out to Calgary Tree Works for a professional assessment.