In message , Andy Burns
writes
AnthonyL wrote:

I've got no ready way of getting up there
even if I wanted to cut the shrub down.

Abseil from the bus-stop?

No ladder available?

A search on slope retention gets any amount of civil engineering hits
but little affordable/installable by a householder.

I know this is d-i-y but no interest from your house insurers?

You need a rot proof grid which can be pegged securely to the slope,
trapping sliding soil but allowing plants to grow anchoring the surface.

18# agricultural Rabbit netting might serve to create in situ gabions.
(roll out some netting, lay on some suitable stone to the lower half and
then fold the top down and secure).

Throw on some soil to encourage plants and do another row higher up.....

--
Tim Lamb