Most owners notice a problem with a big tree only after something changes, and a tree arborist inspection is the usual next step. A limb drops onto the driveway, the canopy looks thin in June or a trench goes in beside the trunk. An inspection by a qualified arborist turns that vague worry into a specific answer about what is happening and what, if anything, needs doing.
Not every change calls for a visit, and some call for one right away. Sorting the two starts with knowing what to look for and keeping a simple record.
Signs That Call for a Tree Arborist Inspection
Decay is the hardest problem to judge from the ground. UC guidance on wood decay fungi in landscape trees warns that decay can stay hidden with no outward sign. It also reports that a 10 percent loss of wood weight can mean a 70 to 90 percent loss in wood strength, and many fallen branches appeared sound beforehand.
Mushrooms, brackets or conks on the trunk or root flare deserve attention for that reason. The same UC page explains that these fruiting bodies help identify which fungus is present. Some species point to localized decay while others signal extensive internal damage.
Visible Changes in the Canopy
Compare the tree with how it looked last year at the same season. Thin foliage, small leaves, early leaf drop and dead twig tips at the top of the crown can all point to stress. Photos taken from the same spot each year make those changes easier to see.
Drought and root problems can look alike from below. The post on recognizing drought stress in established trees covers the signs of water shortage. An arborist can help separate that from disease or root injury.
Root Conditions and Soil Around the Trunk
Roots do most of their work out of sight. Cracks in the soil on one side, heaving near the base or a new lean all suggest movement below ground. Water pooling against the trunk for days after rain may also mean roots sit in poorly drained soil.
Look at the base where the trunk meets the ground. A normal trunk flares out before entering the soil. UC guidance on mechanical injury notes that a mature tree lacking that basal flare often indicates a raised soil grade.
Nearby Construction and Grade Changes
Trenching, new paving and heavy equipment cause damage that may take a long time to appear. The UC mechanical injury page explains that root injury symptoms may not show for months or years. When they do, they include discolored foliage, limb dieback, premature leaf drop, slow growth and wilting.
Anyone planning a patio, utility trench or room addition near a large tree benefits from a look before work starts. The post on planning around trees before patio construction walks through those early decisions.
After a Storm
Wind and saturated soil test trees hard. Cracked limbs, hanging branches, torn bark and a fresh lean deserve a professional opinion before anyone stands beneath the tree. A split where two large stems meet is especially worth reporting.
Stay away from any branch touching a wire. The City of Sacramento advises residents to assume a wire in contact with a tree is energized and to call SMUD. Storm damage involving a street tree goes to the City through 311.
Routine Care Versus Urgent Hazard
Many visits are routine. Pruning young trees for structure, checking a tree before a remodel or reviewing health every few years all fit a planned schedule. Those can wait for a convenient date.
Other situations should not wait. A new lean with soil lifting on the opposite side, a large crack through the trunk or a hanging limb over a walkway all suggest a possible failure. Keep people and cars clear and get a qualified professional out promptly. The post on when a leaning tree needs immediate attention covers that scenario.
What to Document Before the Visit
A short record makes the inspection far more useful. Note when the tree was planted or when the family moved in. List any trenching, paving, grade changes or irrigation changes near the tree, with rough dates. Add the dates of storms and the branches that failed.
Photos help most when they show the whole tree, the base and any damage up close. Include a few shots from past years if they exist. Write down questions in advance so the visit covers everything that worries the household.
Choosing Who Inspects the Tree
The City of Sacramento’s tree questions page suggests looking for membership in groups such as ISA, TCIA or ASCA. It also points to the ISA Certified Arborist and Tree Worker credentials. Ask for proof of insurance and references, and the City suggests collecting three bids for tree work.
Some trees carry legal protection. Work on a City street tree or a private protected tree needs a permit, and the City can help identify protected trees. An inspection report can support that process, though the permit decision rests with the City.
Irrigation Changes Around Old Trees
Water habits shift when a lawn comes out or a drip system goes in. A tree that drank from lawn sprinklers for decades may suddenly get far less water. Other trees get too much when new beds are watered right up to the trunk.
Both changes can show up in the canopy a season or two later. Mention any change in watering to the inspector, including when it happened. Native oaks deserve particular care, since UC guidance notes they evolved without summer water and suffer when the root collar stays wet in warm months.
Questions Worth Asking on Site
Ask what the inspector sees as the main concern and why. Find out whether more testing would change the advice, such as a closer look at the root flare or the inside of the trunk. Request a written summary, because notes made on the spot tend to get lost.
Ask about timing as well. Some work suits a particular season, and some trees should not be pruned during certain months. A clear sense of what comes next keeps the household from guessing.
After the Tree Arborist Inspection
Expect a description of what the inspector saw and any recommended work. Ask which items are urgent and which can wait. Keep the report with the photos so a later inspection can compare conditions.
Recommendations sometimes include monitoring rather than cutting. A tree with minor problems may only need a second look in a year. More posts on these decisions appear in the tree care decisions category.