The method
How this tool reaches its answer
Tree identification comes down to four questions: is the foliage a needle, a scale or a broad leaf; how is it arranged; what is the fruit; and what is the bark doing. Answer those and the list of coastal California possibilities collapses quickly. Where two species still look alike — Bishop pine against Monterey pine, for instance — the interactive key will say so rather than guess.
The second half of the tool values the tree. It uses the Trunk Formula Technique from the ISA Guide for Plant Appraisal: the cross-sectional area of the trunk in square inches, times a regional base rate, times a species factor, times a condition factor, times a location factor. It is the standard method for replacement cost, and it is the reason a mature coast live oak in a front garden is worth far more than the cost of a sapling.
A valuation like this matters when a tree is damaged by a neighbour, a vehicle or a utility. Keep the printout with your photographs; a written report from a certified tree care professional is the version an insurer will want.
The appraisal formula, factor by factor
Rates and bands last reviewed October 2026 · coastal San Luis Obispo County market rates
| Step | How it works |
|---|---|
| Cross-section | π × (trunk diameter ÷ 2)² — the trunk's area in square inches at breast height. |
| Base rate | The regional cost per square inch of replacing a tree with nursery stock of the same size — assumed here at $38, a California figure you can adjust. |
| Species factor | 0.5 to 1.0. A slow-growing native oak scores highest; a short-lived introduced species scores lowest. |
| Condition factor | 0.2 to 1.0, from the crown, the structure, the root plate and any decay. |
| Location factor | 0.4 to 1.0. A specimen in a prominent garden scores higher than a tree in a back field. |
Before you answer each screen
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The foliage
- Pines and firs carry true needles; cypress and cedar carry scale-like sprays that read as flat foliage but are not leaves at all.
- Needles joined at the base in a papery sheath are in a bundle, and that bundle count is the single most useful number in the key.
- Single needles all around the twig rule out every pine on this coast and put you into fir territory.
- The coastal look-alikes are separated here: Monterey pine and Bishop pine both carry bundles of two or three.
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Cones and fruit
- Bishop pine holds its cones closed on the branch for years while Monterey pine opens and drops them — that one habit separates the two coastal pines.
- An acorn makes it an oak, and on this coast that almost always means coast live oak or blue oak.
- A fleshy berry rules the conifers out entirely and points at madrone, pepper or olive.
- Winged seed or a spiky ball means a hardwood rather than a conifer, where sycamore and sweetgum live.
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Bark
- Madrone peels in thin red curls over smooth pale wood — once seen on this coast, never confused with anything else.
- Deep dark furrows on a coastal tree usually mean a mature pine, while thick corky ridges point at Douglas-fir.
- Red fibrous bark with no resin smell is redwood, which keeps it out of the pine group however tall it stands.
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The shape
- A tall narrow spire is the conifer default and a broad rounded crown is the hardwood default.
- A flat-topped spreading crown that leans away from the sea is the classic coastal cypress silhouette.
- A weeping crown of fine foliage on this coast is usually a California pepper or a willow.
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Size, condition, position
- Cross-section is pi times the radius squared, so an 18 in. trunk is 254 sq in. of wood and a 36 in. trunk is four times that.
- Condition runs from 0.2 for a mostly dead tree to 1.0 for a full healthy crown, and it is the factor homeowners most often disagree with.
- A specimen in a front garden scores about twice what the same tree scores in a back field.
- We confirm the species and the condition on site before any figure is relied on.
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What it is worth
- A landmark tree is the one a neighbour describes the street by. It cannot be replaced at that size for any money, which is what makes it worth something.
- A blocked ocean or valley view is the largest single negative a coastal tree can carry, and it is the one an owner can usually do something about.
- The property value is optional and only turns a percentage into a dollar figure. Leave it at 0 and the range is still shown.
- Two more figures come out of this screen: what the wood is worth to a mill, and what the tree adds to, or costs, the property.
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What this tree is
- A possible match is an honest answer and not a failure — two coastal species genuinely cannot be separated without a cone in hand.
- The figure is replacement cost by the ISA trunk formula, not the sale price of the timber, which for an urban tree is almost always lower.
- Keep the printout with your photographs if a tree is ever damaged by a neighbour, a vehicle or a utility.
What the tool cannot know
A browser cannot see a tree. Decay inside a trunk or a root plate, soil and drainage, hidden utilities, access and crane reach, permits, protected species and boundaries are confirmed on site or not at all — which is why every figure here is a range with its method beside it, and why the only price that binds anybody is a written one after a walk-through.