On 19 Feb, 16:08, wrote:
At the "north-end" of this bed I want to put up a little bit of
trellis (1m wide and about 1m high) to add a little bit of height and
to hide an ugly little wall with pipe-work, sockets and a tap on it.
So we have a sheltered, south facing bed with a short bit of trellis
about 1m high and 1 m wide.
Now the question is... what can I grow up it for a splash of colour?

I have on 1mx1m trellis a ceonothus (californian lilac) though I don't
know the variety, in a pot against the wall, south facing just like
your situation. It has thrived there for 3 years and I prune it in mid
spring because it flowers late (early flowering varieties should be
pruned after flowering). So it depends what you are going to get and
you will then know how to prune it. I tie the new stems on the trellis
when they are growing forward. You could also get a cotonoaster
horizontalis, which would give you formidable colours in the autumn
and winter with the berries. I also have one, but it seeked the sun
and now is almost outside my property, over a wall cascading onto the
pavement! I prune it just above the pavement, giving it a little
skirt ) If you prune it regularly you ought to be able to keep on
top of it.

Both could be let to their own devices covering the ugly bits of pipe
you want to hide at the back, but keep it neat and bushy at the front.