it is not yet deemed threatening.

[sanrob]

it is not yet deemed threatening. Make sure you use a qualified tree surgeon: tree of heaven is not easy to remove, because it resprouts suckers

[sdxadmin · Accepted solution]

 so the entire root ball needs to be removed. It also self-seeds, so you will have to be vigilant about making sure no seedlings persist.

[sanrob]

The Arboricultural Association has a list of approved contractors.

[sdxadmin · Accepted solution]

If your neighbours will not agree to remove the tree, either create raised beds lined with membrane to stop soil contamination, or plant in pots. This is less than ideal, but unless the tree goes, there is little else to do