I've been growing cucumber plants from seed this year and everything was going fine until I started trying to move them outside when they were about 8 inches tall. I was acclimating them to the outdoor conditions along with my tomato and pepper plants by placing them outside for a few hours each day, but I always found that the cucumbers wilted by such a large degree when they were outside that I got scared and moved them back indoors after an hour or so. The other plants were fine.
I ended up moving the cucumber plants straight into the greenhouse a few weeks ago, and since then they've gradually got worse and worse, with the leaves becoming very floppy and wilted, followed by the young fruit wilting, and now the entire stems are buckling and collapsing to the soil level. Meanwhile, I kept two plants indoors that were, up until that point, treated identically to the outside plants, and they're thriving (or, at least, not dying).
I'm fairly certain that they have had sufficient water, and the temperature hasn't dropped below about 5°C here since they've been outside, however I forgot to poke holes in the bottom of the plants' growbag, so they spent the first couple of weeks with no drainage. At no point did the soil appear to be saturated, though, and I've since cut some drainage holes about a week ago, but the plants have only got worse.
Does anyone have any idea what I've done wrong? I'm really quite baffled at this stage...
For reference, the seeds I sowed were shop-bought Cucumber Amanda F1 seeds, and I've included photos of both the wilting and healthy plants below.
I am in the UK.
Image of wilting plants:
Image of healthy plant: