Can I cut the branches of my neighbor's tree that hang over my property?

What is actually happening

Branches grow toward light, which in a dense neighborhood means over the fence. Overhang by itself is normal and lawful; the tree owner is not required to keep the canopy inside the lot line. Problems start when limbs contact a roof, load gutters, shade solar panels, drop heavy debris, or carry dead wood over a place people stand. Those are different problems with different remedies, and the first thing a report does is sort out which you have.

The arboricultural catch is that "cut it at the fence" is often the worst possible pruning cut. A limb severed mid-span leaves a stub that decays, sprouts weak growth and can become the hazard you were trying to avoid. Pruning back to a lateral or to the trunk collar is correct arboriculture but may be on the neighbor's side of the line. The right answer is usually a pruning specification both owners agree to, done by a contractor working from the owner's side.

What California law says

• Self-help to the line. A landowner may cut encroaching branches and roots at the boundary at their own expense. Booska v. Patel (1994) 24 Cal.App.4th 1786 added the limit: the right must be exercised reasonably, and a neighbor whose cutting harms the tree can be liable to its owner. More →
• Nothing past the line. Branches on the owner's side are the owner's property. Cutting them is a trespass to trees, and Civil Code 3346 doubles the damages, trebling them for wilful and malicious injury. More →
• Nuisance. Overhang that causes actual damage or substantial interference with the use of your property can be a private nuisance (Civil Code 3479) supporting damages and abatement. Ordinary leaf litter and shade are not.
• Negligence. If the overhanging wood is dead, cracked or otherwise a foreseeable hazard and the owner knows or should know, the owner is responsible for what it does when it falls. Written notice with an arborist's findings is how "should know" gets established. See dead or leaning tree next door.

What your city adds

Most Bay Area cities protect trees above a trunk size threshold or of certain species, and many regulate pruning of protected trees: removing more than a stated share of the live canopy, or any topping, can require a permit and an arborist's involvement whether the owner or the neighbor does it. Oakland, Berkeley, Palo Alto, Los Altos, Saratoga, Mill Valley and Sausalito are among the stricter examples. City by city rules →

What the report does for you

1. Confirms whose tree it is (trunk position) and which limbs cross the line, with photographs.
2. Identifies which overhanging limbs are a problem and why: contact, load, dead wood, structural defect, or none.
3. Writes a pruning specification: which cuts, where, how much, so that any contractor does the same work and the tree is not harmed.
4. States what your city permits and whether a permit is needed.
5. Gives you a document to hand the neighbor, which is usually how a shared pruning job gets agreed and paid for.

Dispute Assessment Report, from $850. Add the $150 neighbor letter and the pruning spec goes over on letterhead. Pricing →

What to do this week

1. Photograph the overhang and any damage, dated, from your side.
2. Do not top or stub the limbs at the fence. If a limb is an immediate hazard, a contractor can remove the hazardous part; otherwise wait for the spec.
3. Tell the neighbor what you intend, in writing, and offer to share a specification.
4. Start a report or text photos to (415) 881-0124 for a free read.

Sources

1. California Civil Code § 833, ownership of trees.
2. California Civil Code § 3346, damages for injury to trees.
3. California Civil Code § 3479, nuisance.
4. Booska v. Patel (1994) 24 Cal.App.4th 1786.