The useful part, first
- Ask for a diagnosis before a treatment.
- Get the proposed work in writing.
- Use qualified professionals for large or hazardous tree work.
Describe the concern without deciding the cure
A tree dropping leaves, showing a damaged limb or leaning differently deserves attention, but the homeowner does not need to prescribe the solution. Photograph the concern from a safe location and note when you first saw it. Keep people away from an area that may be hazardous.
UC Agriculture and Natural Resources recommends informed decisions when hiring an arborist, including understanding the suspected problem and the proposed response. Ask whether the visit is an assessment, a pruning estimate or both. Those services may produce different kinds of information.
Request a clear recommendation
Ask the arborist to identify the tree, explain the observed condition and describe the options. If removal is recommended, ask why pruning, monitoring or another approach would not address the concern. If treatment is proposed for a pest, ask how the pest was identified and what evidence supports the treatment.
Have the scope identify the work, cleanup and any follow-up. Ask how nearby structures, landscaping and access routes will be protected. A phrase such as trim the tree is too broad to tell you what will actually happen or what the finished result is intended to achieve.
- What problem are we trying to solve?
- What alternatives are reasonable?
- How will we know whether the work helped?
Check the people and permissions
Verify relevant credentials, licensing and insurance for the actual work. Ask who will perform the job and whether subcontractors are involved. For work near utility lines, contact the utility and use professionals qualified for that situation. Do not attempt overhead or large-limb work yourself.
Before removal or major pruning, ask the city or county about applicable tree protections and permits. Property boundaries and HOA requirements may also matter. A contractor's availability tomorrow does not settle those questions. Keep approvals and scope documents together before work begins.
Think beyond the day of service
Ask what care the tree needs after work and which changes should prompt another call. If irrigation or nearby construction is involved, explain those conditions to the arborist. A recommendation made without that context may not address the full concern.
Save photographs and the assessment so a later visit has a starting point. If replacing a tree, discuss mature size, roots, shade, utilities and wildfire considerations before choosing a species. The goal is a tree that fits the property over time, or a well-supported decision when it cannot remain. You can protect both safety and the landscape by asking for evidence before agreeing to irreversible work.
- Next step: request a written assessment and scope before approving significant pruning or removal.
Sources & further reading
Sources checked September 19, 2026. Requirements, schedules and availability can change. Check the linked source before acting.
General homeowner education. Follow equipment instructions and local requirements. A qualified professional can evaluate your property and circumstances.
