re - the window box and what will grow in it...
 

It faces the way the sun sets.
It gets about 3 hours direct sunlight in the afternoons.
I'm not really fussy what I grow in there - I had thought herbs (it's
off the kitchen wall) and something flowering (it looks pertty bad
empty).

It isn't that large though - about 50cm deep and 1.5 metres tall.