Duluth trees earn their keep. They block Lake Superior wind, shade your yard through short summers, and hold the soil together on all those hillside lots. So when one starts looking off, it’s easy to brush it aside and hope it bounces back next spring.
Sometimes it does. Sometimes it doesn’t, and by the time the answer is obvious, you’re looking at a hazard instead of a tree.
The good news is that trees rarely die overnight. They send signals for months, sometimes years, before they actually go. You just have to know what you’re looking at. Here are seven signs that tell you a tree is struggling, and what each one usually means.
1. Bark That’s Peeling, Cracked, or Missing
Healthy bark is a tree’s armor. It keeps moisture in and pests out. When you start seeing large sections of bark falling off, deep vertical cracks, or bare patches of exposed wood, the tree has likely lost the ability to protect itself.
Run your hand along the trunk. If bark comes away easily in big chunks, especially near the base, that’s not a good sign. A little peeling on species like birch or maple is normal in small amounts. Widespread loss, paired with dry or brittle wood underneath, usually points to disease or severe stress.
Duluth’s freeze thaw cycles are hard on bark too. Sharp temperature swings in late winter can cause frost cracks, which sometimes heal fine on their own but sometimes open the door for decay to set in.
2. Deadwood in the Canopy
Look up before you look anywhere else. A tree that’s shedding branches from the top down, or that has large sections of bare, brittle limbs mixed in with healthy growth, is telling you something.
A few dead twigs at the tips aren’t a crisis. Every tree has some. What matters is the pattern. If dead branches are spreading inward toward the trunk, or if you’re seeing whole sections of canopy with no leaves while the rest of the tree looks fine, the tree is likely redirecting energy away from the parts it can’t sustain anymore. That’s usually a sign of root damage, disease, or a pest problem working its way through the tree.
This is also one of the more dangerous signs for homeowners. Dead branches, sometimes called widowmakers for a reason, can drop without warning. If you’re seeing this near your house, driveway, or anywhere people walk, don’t wait to have it looked at.
3. Leaves That Are Thinning, Off Color, or Showing Up Late
Every species has its own leaf out schedule, but you learn what’s normal for your own trees over a few seasons. When a tree that used to fill out fully every May starts showing sparse, patchy leaves, or when leaves come in smaller than usual, take note.
Watch for yellowing or browning that shows up early in the season, well before fall color would explain it. Also watch for leaves that wilt even after a good rain. That combination often means the roots aren’t pulling up water and nutrients the way they should, which points to root damage, compacted soil, or disease below ground where you can’t see it.
Ash trees in particular deserve extra attention here. Emerald ash borer has been confirmed in the Duluth area, and thinning canopy with D shaped exit holes in the bark is one of the clearest signs of an infestation. If you have ash trees on your property, this sign is worth checking every single year.
4. Fungus Growing on or Near the Trunk
Mushrooms, shelf fungus, or conks growing directly on the bark or clustered around the base of the trunk are almost never a good sign. Fungus feeds on dead or decaying wood, which means if it’s growing on a living tree, decay has already started somewhere inside.
The tricky part is that a tree can look perfectly healthy above ground while rotting from the inside out. That’s exactly why fungus at the base is worth taking seriously, even if the canopy still looks green and full. Internal decay weakens the structure long before it shows up anywhere else, and it’s one of the leading reasons otherwise healthy looking trees fail during storms.
If you spot shelf fungus, bracket fungus, or mushroom clusters at the root flare, it’s worth having someone take a closer look rather than assuming it’s cosmetic.
5. Vertical Cracks or Splits in the Trunk
A crack running up and down the trunk, especially one that’s widening or that you can see daylight through, is a structural red flag. These cracks often form after storm damage, frost injury, or as decay spreads and weakens the wood from within.
Duluth gets its share of high wind events off the lake, and a trunk with an existing crack is far more likely to fail under that kind of stress. If the crack runs deep into the wood, or if you notice sap or moisture seeping out around it, the tree’s structural integrity is compromised, and that’s not something to wait on if the tree is near your home or a place people gather.
6. Leaning That Wasn’t There Before
A tree that has always grown at a slight angle isn’t automatically a problem. Trees adjust to sunlight and wind over decades, and a lifelong lean is often just how that tree grew.
What matters is a new lean, or one that’s getting more pronounced. This usually means the root system is failing, often because roots have rotted, been damaged by construction or heavy equipment, or lost their grip after prolonged soil saturation. Check the base of the tree for soil that’s cracked, lifted, or heaving on one side. That’s often a sign roots are pulling out of the ground rather than holding it.
A newly leaning tree, particularly a large one, is one of the more urgent signs on this list. Root failure can happen gradually and then give out all at once.
7. No New Growth for a Full Season
Trees put out new growth every year, whether that’s fresh shoots at branch tips, new leaf buds, or a visible flush of green in spring. If a full growing season passes and you don’t see any new growth at all, the tree may have stopped functioning the way it needs to in order to survive.
This one takes a bit of patience to confirm. Compare the tree to its past seasons if you can, or compare it to a similar healthy tree nearby. A tree that used to add a noticeable amount of new growth each year and now shows none is likely in serious decline, even if parts of it still look green.
What to Do If You Spot These Signs
One or two of these signs on their own don’t always mean a tree is dying. Trees deal with stress from drought, storm damage, and seasonal changes all the time, and plenty recover. But when you start seeing several of these signs together, especially deadwood combined with fungus, cracking, or a new lean, it’s worth getting a professional opinion before deciding what to do next.
A tree that’s dead or dying isn’t just a landscaping issue. In a place like Duluth, with steep lots, lake effect wind, and heavy snow loads, a compromised tree near a house, driveway, or power line is a real hazard once it starts to fail.
Twin Ports Tree Service has spent years assessing trees across Duluth and the surrounding area, and we can tell you honestly whether a tree needs to come down, can be saved with some pruning and care, or just needs a little time to bounce back. If you’re not sure what you’re looking at, give us a call at 218-993-6228 and we’ll take a look.