Tomato feed is ok, also if you go to the garden centre, then you can by organic seaweed which you can dilute, use this on a variety of veg, julien.

Hi there marshmallow,

I use Tom food too, I am growing cucs in large pots this year, as I have found grow bags dry out to quick, and also can be over watered. I shade my cucs to as they can scorch and the leaves become papery.

Good luck with them this year.

Happy gardening.

Thank you both. I'll give that a go. I always seem to have trouble with cucumbers. Last year red spider mite which I didn't identify soon enough.
They are fairly shaded and are in the greenhouse border so should not dry out IF I WATER THEM ENOUGH. Which i rarely do.