john west wrote:
Planted a Victoria plum tree some time ago in a black plastic recycle
box. Its been growing really well. when i came to move it (i put it
in the box because i knew i would move it) i found a long tap root (about
a
finger thick) had escaped from the box into the soil below.

I cannot get this root out of the ground without breaking it.

Would this result in serious damage to the little plum tree or would
it recover from this? Thanks.

If it were mine, I'd cut the plastic box into pieces in situ and shake off
as much of the soil, then carefully dig down to free the tap root saving as
much as possible before re-planting.