Struggling with Cucumber — would appreciate advice

I want to be honest: I'm not getting great results with Cucumber and I'm not entirely sure why. aphid colonies on brassicas and soft growth has been a recurring problem despite my attempts to address it. I've been focusing on consistent deep watering rather than frequent shallow watering based on everything I've read.

far superior flavour versus supermarket produce is there in glimpses, which tells me the plant has potential in my conditions. I have it in a greenhouse or polytunnel for season extension which might not be ideal. clearing beds and preparing soil with compost in autumn showed some improvement. Two stars for now — not the plant's fault, but not a success yet. I'll update if things improve.