Ian McLeod writes
I live outside Lanark which is about 30 miles South of Glasgow. The bank is
at the south end of the garden and so the slope faces north. The soil is
very sandy and gets sunlight (when it's around!) most of the day. There are
no other plants on the bank at our side, but over the wire fence is a
farmer's field which alternates between grazing for sheep and winter wheat.
As it is along the edge of the field there are also quite a lot of nettles,
thistles etc.

Sounds like the one I built, though mine is in a semi-circular D shape
and a lot further south. But if its sandy and therefore well drained,
you can get quite a lot of plants to grow in the bank itself. You might
even try adding some more well-wedged-in rocks. All mine seem to love
being in the side of the bank, judging by the amount of self-seeding.
You just need to jam them in horizontally wedged between the rocks, and
they do the rest.

On top I grow euonymous, ceanothus, broom, and escallonia to provide
some protection. On the north facing bank I have lamium, woolly thyme,
parahebe on top, various sedum, various saxifraga, raoulia, various
sempervivum and so on down the bank. Amazing displays of lots of tiny
flowers often on long stems sticking out from the plants hidden in the
rocks.

Sometimes they can be propagated by just plucking off a stem and wedging
that in with a stone to hold it in place. A few weeks later its growing
new leaves!
--
David