Cucumbers and Cucurbits

[sweetpea]

Of course it is entirely possible to grow cucumbers and tomatoes without a g'house although i would exempt all female cucumbers.
there are ridge cucumbers which you would normally grow outdoors and many tomato varieties are hardy enough to be out there too.
Telegraph and telegraph improved are just two cucumber varieties I have grown wholly outdoors as I didn't have a g'house back then and I am sure many more have beed raised since then.
I know it is rather subjective but I reckon the flavour of stuff like that grown in the soil has a superior flavour to that grown in gro-bags or pots.

[Cherry]

I agree that the growing medium must affect the flavour of fruit and veg.

[daitheplant]

Not so much the medium Cherry as what you feed them. Overfeed cucumbers and they get bitter, underwater tomatoes and they develop tough skins and split.