Most trees that come down in a Cape Town storm were showing the signs a tree is dangerous for months before they fell: dead branches in the crown, fungus at the base, soil lifting on one side. You do not need training to spot most of them. You need ten minutes, a slow walk around the tree and a clear idea of what each finding means.
This checklist works from the top of the tree down, then covers lean and storms, with what to do about each finding.
How to check for the signs a tree is dangerous
Pick a calm day, walk all the way round the tree and stand far enough back to see the whole crown. Take a photo from the same spot every time: a lean or thinning crown is hard to judge from memory, but easy to see next to last year’s photo.
Do it at least once a year, ideally in autumn before the winter cold fronts arrive, and again after any big storm or building work near the roots. Trenching and soil compaction kill roots slowly, so a tree can start declining two or three seasons after the builders have left.
Think about what the tree could hit. A dead limb over an empty corner of the garden can wait a few weeks. The same limb over a bedroom, driveway or neighbour’s roof cannot.
The canopy: deadwood, thinning and hanging limbs
Start at the top, because that is often where trouble shows first. Look for:
- Dead branches in the upper crown. Bare, grey twigs among healthy leaves are often the first visible sign of a root problem below.
- Thinning foliage that gets worse each season, or leaves that scorch and colour early in late summer.
- Hanging or broken limbs caught in the crown, which can drop on a calm day.
- One-sided crown loss, often on the side facing the south-easter.
Is it dead, or just dormant?
Deciduous trees such as oaks and planes look dead every winter, so check them in spring before deciding anything. For an evergreen, or any tree that should be in leaf, try the scratch test: scrape a small patch of bark on a few twigs with your thumbnail. Moist green tissue underneath means that part is alive. Dry brown all the way round means it is dead. A completely brown crown in summer, or leaves that browned and never dropped, usually means the whole tree has gone.
What to do: A few dead branches on an otherwise healthy tree can simply be cut out. Widespread dieback needs a proper diagnosis, which we cover at the end.
A dead tree is a different matter. Dead wood turns brittle, so it snaps in the wind instead of bending, and dead gums and pines are known for dropping heavy limbs without warning. It only gets more dangerous to climb, so plan its tree removal before the next winter if it could reach a roof or boundary.
Palms need their own look. Dead fronds and heavy seed bunches hang on until the wind tears them loose, and they come down hard. Regular palm cleaning takes them off before they fall.
The trunk and main limbs
- Cracks or splits running along the trunk or down from a fork.
- Included bark, where two big stems meet in a tight V with bark squeezed between them instead of a solid ridge of wood. These joins often split under load.
- Cavities and old pruning wounds that never sealed over, especially where heavy limbs were lopped years ago.
- Bark falling away in sheets, with smooth, grey wood showing beneath.
- Signs of borers: tiny holes, sawdust-like frass, oozing gum or dark sap. On box elders, planes and oaks, tiny holes with a white crust can point to polyphagous shot hole borer.
What to do: One small crack or an old wound is something to photograph and watch. A long split, a cavity in the main stem or a cracked fork over a structure is a reason to have the tree looked at soon. If you suspect shot hole borer, never move the cut wood or firewood to another property, because the beetle travels in it.
The base and roots
Some of the most serious problems hide at ground level. Clear away mulch or groundcover so you can see the root flare, where the trunk widens into the roots.
- Fungal brackets or mushrooms on the base of the trunk or in the root zone. This is the classic outside sign of decay inside.
- Soft, dark or crumbling wood at the root flare, common after a wet winter.
- Soil lifting or cracking on one side, which means the root plate is moving in the wind.
- Cut or damaged roots from trenching, paving or building work under the canopy.
- Soil or rubble piled against the trunk, which keeps the bark wet and invites rot.
What to do: Fungus at the base and soil heaving on one side are two of the most serious signs a tree can show, especially together. Treat them as urgent if the tree could reach a building. Roots that lift paving, crack walls or get into pipes are a slower problem, and our guide to tree roots damaging walls and paving covers the options. If a tree does come out, stump grinding stops the old stump rotting in place and attracting termites.
Lean: when it matters and when it does not
Plenty of trees grow with a lean and stand safely for decades, because the trunk and roots have grown to carry it. What matters is change.
- A lean that is new, or has increased since last year’s photo.
- A lean that appears after heavy rain, when the soil is saturated.
- Cracked or lifted soil on the side away from the lean, where roots are being pulled up.
- A lean towards a house, wall, driveway or power line.
What to do: A sudden or growing lean, especially with soil lifting at the base, means the root plate is failing. Keep people and cars out of the area the tree could fall into and get help straight away. An old, stable lean only needs watching.
After a storm
Cape Town tests trees twice a year: the south-easter all summer, then winter cold fronts with north-westers and waterlogged soil. Once the wind drops after a big blow, walk the garden again and look for:
- Hanging or partly broken limbs caught in the crown.
- Fresh cracks at forks or along the trunk.
- A new lean, or soil lifted at the base.
- Trees or limbs resting on roofs, walls, fences or other trees.
What to do: If a tree or limb is resting on a structure or hung up in another tree, do not try to cut it yourself. Timber under load can spring violently when it is cut. Keep everyone clear, stay well away from any fallen power lines, and photograph the damage for your insurer before anything is moved. Our guide to emergency tree situations covers the first steps. Our team does storm damage clean-ups, lifting timber off structures with ropes and rigging and taking all the waste away.
Arborist or felling team: who to call
Some findings point clearly to removal: a dead tree, a hollow trunk, rotten roots or a root plate on the move near a building. Others are less clear. A tree with spreading dieback, oozing sap, pest damage or unexplained leaf drop may well be treatable, and the right person to diagnose it is an independent arborist, sometimes called a tree doctor.
A good arborist looks for the cause rather than the symptom, and can advise on treatment, watering or pruning that may save a structurally sound tree. If the verdict is that it has to come down, our team can quote for taking it out safely.
Whatever you find, keep your photos and notes. Insurers can question claims where a tree was visibly dead or dangerous beforehand, so a record that you checked and acted is worth having.
If your walk-around turned up something that worries you, WhatsApp a photo to 071 799 1993 or use our contact page to book a free site visit and written quote.