wrote:
[...]
The new bed is on the only south-facing wall, which gets a little
shade from a tree in someone else's garden also, unfortunately.
It's
about a 6 foot isosceles triangle and I want to use it as my
kitchen
garden (aww, how sweet!).

So, I was thinking of planting an espaliered apple tree against the
south-facing wall. Ideally I'd like to plant a vine with edible
fruit, but we live in the Morecambe Bay area, let's be realistic
here. An apple tree is probably about my speed. At least we
hardly
ever get frost...

Would this be a good idea? What kinds of apple trees would be best?
When do you plant apple trees?
[...]

An apple tree would be fine -- ask for recommended varieties at a
local specialist nursery. Espaliers are more work than natural forms,
by the way. But its roots wouldn't mix happily with vegetables in
such a small area.

You may find some inspiration at the Square Foot Gardening website:
http://www.squarefootgardening.com/

It's very American, but does put a new slant on container growing.

--
Mike.