K wrote:

Forget cucumbers - they really need a greenhouse.


I have never had a problem growing cucumbers outdoors in a sunny spot.
Both my outdoors plants currently have 2 small cucumbers each on them
and lots of flowers (I started them early indoors and they went outside
mid-May).

It's too late to start from seed this year but should be possible to
find young plants around. Always a good idea to ask on Freecycle as
people often have surplus plants if germination rates were good and are
happy to give them away.