I have a tree overhanging from the neighbour and cannot remember the species.
Its regularly dropping leaves and small branches
I have a row of Lilly Pilly's under this tree. The ones directly under this tree are stunted and look diseased with multiple dead branches. The ones beyond it are fine and growing well
Do the dropping leaves pose a toxic risk to any plants underneath?
Thanks
Generally one species will not be toxic to another so dropping foliage and twigs should present no problem. However if the higher plant is dropping disease or pests then that's a different matter. This kind of thing is impossible to diagnose remotely so I suggest you take a branch with some foliage on it to your local nursery who will be able to inspect it and see if there is any entrenched disease or signs of pest infestation. The other thing to consider here though is - is your neighbour's plant casting too much shade over your Lilly Pillies? If so then this could be the reason why they are ailing a little
A further update - the tree in question is an Ulmus parvifolia or Chinese Elm. These are considered to be slightly allelopathic in that its roots exude chemicals that discourage other plants growing close by thereby safeguarding its own access to nutrients. However the effect is generally not severe and affected plants tend to just be a bit less vigorous rather than dying off completely. So this could well be the reason - e.g. not from dropping foliage but from the root systems underground.