Last year our 15yr old Laburnum started leaning over pecariously but it
seemed to be otherwise okay (if a bit wobbly). This year however after
flowering the leaves all turned yellow & withered and when I cut a branh
off, the heart wood was black. I suspect some sort of fungal infestation
(perhaps entered through damaged roots?)

Anyway, I've chopped it down and dug up as many of the roots as I can. Is
it safe to replant a new tree in the same spot? (It won't be another
Laburnum).

Tim