Tree Risk Assessment Levels Explained
What a Level 1, 2, or 3 tree risk assessment actually involves, and why the level matters as much as the result.
A tree risk self-check worksheet you can use right now, no email required
Print this page or pull it up on your phone and walk your property, tree by tree. It will not replace a professional assessment, but it will tell you which of your trees actually deserve one first.
Skip ahead to a real assessmentHow to use this tree risk self-check worksheet
This is meant to be used outside, at the tree, not read once and forgotten. For each tree on your property that gives you any pause, walk through the four groups below — trunk and base, canopy, roots and site, and history — and note anything that matches. One match is not a verdict; it is a reason to look closer or get a professional opinion. Several matches on the same tree, or any single serious-sounding one (a large cavity, a fresh crack, visible root failure), is a reason to stop guessing and get it assessed soon rather than waiting for the next windy week to decide for you. Print this page from your browser to take it outside with you, or just keep this tab open on your phone. What this worksheet cannot do is replace an actual tree risk assessment — see our page on assessment levels for what that involves. It is a screening tool, the same job a Level 1 assessment does across many trees: it tells you where to look closer, not what the final answer is.
Walk the trunk and base first
- Look for cavities, cracks, or soft/spongy woodA hollow-sounding knock, a visible cavity, a vertical crack running any real length up the trunk, or bark that gives under light pressure instead of feeling solid — any of these on their own is worth a professional look, especially on a larger tree.
- Check for mushrooms, conks, or fungal growth at the base or on the trunkFungal fruiting bodies growing directly from a trunk or the root flare are one of the more reliable visible indicators of internal decay, even when the rest of the tree looks perfectly healthy above it.
- Note any lean, and whether it is new or has always been thereA lean that has genuinely been part of the tree's shape for years is a different situation than a lean you're fairly sure is new, or one where the ground near the base looks disturbed, heaved, or cracked — that combination suggests a root failure in progress.
- Check where major limbs attach to the trunkA narrow, tight V-shaped attachment with visible included bark, or a crack forming right at a major limb's attachment point, is a structurally weaker joint than a wide U-shaped attachment — and it is exactly the kind of thing that is easy to miss from a casual glance but obvious once you know to look for it.
Then the canopy, roots and site, and history
- Canopy — a significant share of dead branches, or dead branches concentrated on one sideScattered small deadwood is common and often not urgent; a large share of the canopy dead, or deadwood concentrated on one side while the rest looks healthy, points toward a specific stress or damage affecting part of the tree rather than general aging.
- Canopy — branches that look unusually heavy, long, or extended for their diameterA long limb with a lot of weight at the end and comparatively little supporting diameter near the trunk is a leverage problem — it does not need to be diseased to be a structural concern, especially over something worth protecting.
- Roots and site — visible root heave under nearby pavement, or roots cut during recent constructionHeaving pavement means roots are pushing something up, which tells you about their spread but not their health. Roots that were cut or damaged during a driveway, foundation, or utility project — even years ago — can compromise a tree's stability well after the work is finished and forgotten.
- Roots and site — standing water, recent grade changes, or construction near the root zoneAny of these can stress a root system in ways that take months or years to show up in the canopy above — the visible symptoms often lag the actual cause by a long time.
- History — the tree has dropped a large limb before, even onceA prior large-limb failure, especially one with no obvious explanation like a storm, is one of the strongest indicators that something structural is going on and worth a real look rather than a wait-and-see approach.
- History — recent significant wind, storm, or fire-adjacent stressA tree that came through a recent storm without an obvious failure can still have sustained a hidden internal injury — see our guide on what to do about a storm-damaged tree for the specific signs that follow a weather event.
Questions people ask
Is this checklist a substitute for a professional tree risk assessment?
No. It is a screening tool meant to help you decide which trees on your property deserve a closer professional look, the same job a Level 1 assessment does across many trees at once. It cannot tell you what is happening inside a trunk, and it is not a final answer on any specific tree's safety.
What should I do if a tree matches several items on this list?
Treat it as a priority for a real assessment rather than continued monitoring on your own, especially if anything nearby — a structure, a driveway, a place people or cars regularly are — could be affected if the tree failed.
What if a tree matches nothing on this list — does that mean it's fine?
It is a reasonably good sign, but not a guarantee, particularly for eucalyptus, which can drop limbs with little visible warning even on trees that otherwise look entirely healthy — see our page on eucalyptus and palm tree risks for why those two species need a slightly different kind of attention than this general checklist covers.
How often should I walk my property with this worksheet?
A seasonal check is a reasonable habit for most properties, plus an extra pass any time after a significant storm, high-wind event, or nearby construction that could have disturbed a root zone.
Can I print this page?
Yes — use your browser's print function to print or save it as a PDF to take outside with you, or just keep it open on your phone while you walk the property.
Related reading
Signs a Tree May Be Dangerous
The ground-level warning signs worth knowing, what each one generally means, and where a look from the yard stops being enough.
Eucalyptus and Palm Tree Risks in San Diego
Why San Diego's two most common mature tree types fail differently than a typical broadleaf tree, and what to actually watch for.
Found something on the checklist? Get it looked at properly
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