Cucumber confusion!

[Ktcabster]

It’s my first year attempting to grow cucumbers - I have 4 plants in the bed of my greenhouse (from the same pack of seed) and they’ve all grown brilliantly. The problem is, two of the plants have plenty of fruits growing but the other two continuously produce only the male flowers with no female fruit flowers at all. Should I be doing anything to promote the female flowers? I haven’t treated any of them any differently, so I have no clue where I’ve gone wrong!

[Penellype]

What variety are they? It should say on the packet. There are 2 sorts of cucumbers some which produce all female flowers and some which produce male and female, and they need treating differently. Indoor cucumbers should be all female and you should remove any male flowers as pollinated fruit will be bitter and inedible. Outdoor (ridge) cucumbers need pollinating to set fruit.