Your Neighbor's Tree Over Your Yard: Illinois Rules

Few property questions generate more bad advice than this one. A neighbor's tree hangs over your yard, drops limbs on your garage, or looks dead and aimed at your bedroom - and everyone you ask has a confident, different answer.

Here is the practical picture in Illinois. This is general information, not legal advice. For a dispute that is heading somewhere serious, or a tree you believe is a genuine hazard your neighbor refuses to address, talk to a lawyer and put your concerns in writing.

Who owns the tree

Ownership follows the trunk, not the canopy or the roots. If the trunk is entirely on your neighbor's side of the line, it is their tree, full stop - even if two thirds of the branches are over your yard and the roots are under your lawn.

A tree whose trunk sits on the boundary line is generally treated as jointly owned by both property owners, which means neither one gets to remove it unilaterally. Boundary-line trees are where most of the genuinely ugly disputes come from, and they are the situation most worth getting proper advice on before anyone cuts anything.

What you are allowed to cut

Illinois follows the common "self-help" rule that most states use. In practical terms:

• You may trim branches and roots that cross onto your property, at your own expense, back to the property line.
• You may not cross the property line to do it. No reaching over to make a cleaner cut, no working from their side without permission.
• You may not cut in a way that damages or kills the tree. The self-help right covers your airspace, not the tree's survival. If your trimming kills the tree, you can be liable for its value - and mature tree values in court are not small numbers.
• The fruit is theirs. Apples hanging over your yard still belong to the tree's owner, even if they fall on your side. This matters almost never, and it comes up constantly.
• You pay for your own trimming. Removing branches over your yard because you want them gone is your expense, not theirs.

One more that catches people out: "I'll just have the crew take it back to the line" is only safe if the crew knows where the line is and understands the kill-the-tree limit. A badly executed line-cut on a mature tree can leave you holding both the damage claim and the bill. Any crew doing boundary work should be explicitly told where the line runs, and the cuts should be proper pruning cuts - never a flat chop back on one side. See tree trimming cost for what the work involves.

Who pays when it falls

This is the part that surprises people most. The general rule:

A storm dropping a sound tree is an act of nature, and insurance treats it that way. Your carrier covers the damage to your structure and may pursue theirs if there is a negligence case. The full version is in does homeowners insurance cover tree removal.

The hazardous-tree case, and why written notice matters

Negligence is where the outcome changes. If your neighbor knew or should have known the tree was hazardous and did nothing, they may be liable for the damage it causes. "Should have known" is doing real work in that sentence, and it is why documentation matters more than anything else you can do.

If you believe a neighbor's tree is genuinely dangerous - a dead ash, a split trunk, a new lean toward your house:

1. Document it. Photograph the tree, dated, from several angles. Note what specifically concerns you.
2. Get a professional opinion in writing. An arborist consultation that identifies the defects gives you something concrete, not an opinion exchanged over a fence.
3. Give written notice. A polite letter describing the condition, attaching the photos and the arborist's assessment, delivered in a way you can prove - certified mail, or email you keep. This is the step that converts "they should have known" into "they were told."
4. Keep a copy of everything.

Written notice is also the step most likely to just solve the problem. Plenty of homeowners genuinely do not know their ash is dead - and on the North Shore, most ash are. A dated photo and an arborist's note often gets the tree removed without any conflict at all.

Shared removals and the practical path

The outcome that actually works most often is neither self-help nor a lawsuit: the two of you split a removal. A hazardous boundary tree, or a dead tree that threatens both properties, is cheaper and faster to handle jointly, and a crew can quote it as one job with one access plan.

If you go that route, put the split in writing before the work - who pays what share, who the crew is working for, whose yard the equipment comes through, and what happens to the wood and chips. Ten minutes of writing prevents the entire category of argument that starts after the tree is down.

Before you touch anything

Three things to confirm:

• Where the line actually is. Fences are frequently not on the line. A plat or survey settles it.
• Whether a permit is required. Several North Shore towns regulate removal of healthy trees over a size threshold, including on private property. Our permit guide covers who requires what.
• Who the crew is working for. The person who hires the crew owns the decisions and the liability for the work.
• Whether the tree belongs to either of you. If it is in the parkway between sidewalk and street, it is probably the village's and neither of you gets to decide - see parkway trees: is it yours or the village's.

Boundary trees come up regularly in Winnetka, Kenilworth, Wilmette, Glencoe, Evanston, and anywhere lots are narrow and the trees are old. For a written assessment you can hand to a neighbor - or a quote on a shared removal - request a free on-site estimate, or start with the online estimate tool for a quick range.