OK
The tree belongs to you, the branches grow where they may, but if they cross the boundary line the neighbour can cut them back to the imaginery vertical line of the boundary.
Yes, returning branches etc. This also means they cannot pick a lemon or a plum from your tree and consume it, but can rake up all the rotting fruit and return it to your land if they choose to do so.
I have neighbours to one of my places who bought their place around four years ago. The trees have been there since about 1974.
My property is to the south of the boundary, and of course the trees grow towards the sun.
I have instructed the property manager to tell the neighbours they are welcome to shear the trees off vertically if they like. Regrowth will occur on their sunny side of the tree. They can do as they wish with the prunings but I do not want them back.
I have also stated that I am happy to remove the trees altogether. The subsequent loss of privacy will affect each property unless they are prepared to plant along their side of the fence. Planting along my side will produce spindly growth because of the fence shadow and the branches will grow over the fence again.
However, in the interest of health and safety I have asked said property manager to organise a general pruning of all trees on my property. This was last done about three years ago and cost nearly $500.
The crew chainsawed their way around the entire place, including walking around the roof with a mini chain saw attached to a long pole, reaching out to wizz off anything close to my roofline. They then mulched everything to sawdust and roared off into the sunset.
While the crew is there the neighbour may like to ask for a quote for their side of the fence.
Tree Roots:
I had an interesting case (Body Corporate) where four units had suffered extensive subsidence of the strip footings and the brick work had cracked severely, to the point that parts of the wall had become unstable.
The engineer's report blamed the Lilly Pilly tree plantings (a long line of them planted alternatively with swamp Melaluca) on the adjoining property. The neighbouring house was weatherboard, and had suffered no damage. It probably had red gum sole plates which had either decomposed or were not affected by the shrinking of the subsoil.
However, Lilly Pilly love water. Their root systems are extensive. The tree had dried the subsoil allowing the strip footings to 'roll', and as bricks and mortar are not elastic the couple of millimetres roll was enough to twist the wall and break the mortar open.
Solution:
The trees were cut down and the roots poisoned. A trench was dug along the neighbours boundary and this was filled with coarse aggregate and soaker hoses were laid in the trench. The hoses were left to drip for three months, after which hydrostatic tests were conducted on the subsoil.
When this had hydrated to an acceptable margin, the footings were dug out, the wall underpinned and the brickwork repaired.
This work cost over $10,000 (four years ago). The matter had been referred to VCAT and the neighbour was instructed to contribute to the cost of the rectification works with the body Corporate insurance covering the balance.
Some time later while inspecting a property as a Buyer's Agent, I was astonished to come across exactly the same situation. The bricks had twisted so far off line you could put your arm in the gap. Surprisingly, inside the house there were no gaps or cracks, the timber frame on stumps was not affected, again the damage was with the strip footings. However, with this house, the roof members had also twisted. The thirsty neighbouring Lilly Pilly directly opposite the main cracking had also had its natural drip zone affected by this house concreting the driveway, thus reducing the soak available to the tree.
Law of Tort:
Duty of Care:
Rylands v Fletcher has established that if anyone should bring anything onto their land which, by it's escape, causes harm to another, then that person is responsible for the harm.
So if you plant, or allow to remain, trees which have extensive root systems you are responsible for the damage caused by the tree roots.
It is not reasonable to expect that your neighbour will dig to expose the roots.
However, tree branches are accessable and the neighbour has the right to remove any unwanted foliage which may overhang their title.
Trees shed branches. Trees can look healthy, then along comes rain and a strong wind, and the branch is off or the tree is uprooted.
The damaged householder's insurance company would firstly assess and attend to the damage, but it would remain to be determined whether the owner of the tree was negligent. Just because you wake up with a large branch in bed beside you does not mean your neighbour has been negligent. Not everything has to have a hero and a villain.
Natmarie, I would consider the issue with the neighbours seriously. Lilly Pilly (unless a cultivar bred for the purpose) are notorious for damage as I have described. They also drop squishy berries and other nasty gardenny things guaranteed to infuriate fussy neighbours. More to the point, this tree may damage your mother's own property particularly driveways and paths, if not the strip footings of her house.
Inspect the tree, location, etc logically. If it is logical, remove it and replace it with insipid boundary trees such as James Sterling, Pivot or perhaps a Camellia, planted well within your mother's boundary.
She may grieve for the Lilly Pilly for a week or two but that is better than years of bickering. Replace it with a Lilly Pilly in a safe, open space such as the middle of the lawn (or move the one you've got).
My mother had two magnificent Lilly Pilly, planted midway down their 200 ft long block, These magnificent sentinels produced huge amounts of berries and were a source of great joy. However, although they had been deliberately planted out of harms way even then they buckled the concrete paths in that area of the yard.
Good luck, hope the situation can be resolved without fisticuffs!
Cheers
Kristine