I planted the seeds of these gherkins and they all grew. I then planted them into a larger pot but they've grown very big now and the pot is quite tight for them. I want to transplant them but I also don't want to upset them while they're having flowers. However I'm worried that they won't have any fruits due to lack of space to grow well. So far a few of the flowers have dried and fallen off. What would you recommend?
What we see here are not thriving gherkins, but plants sending out flowers in a last-ditch effort to produce offspring before succumbing to adverse conditions. Ok, I may be exaggerating, but with just two leaves each, there’s simply not enough photosynthesis going on to sustain a real harvest.
I wouldn’t worry about the flowers, rather separate the plants before the roots get tangled up completely. This pot is way too small to grow them in. For cucumbers/gherkins in pots, aim for at least 20 liters of soil, and you will likely need some support like a trellis.
Unless you have a specific breed, the female flowers will need to be pollinated to produce fruit. So either get the plants outside and let things happen naturally or pick an open male flower and “play bee”. Btw., those first flowers were almost certainly male flowers, so you didn’t lose anything when they fell off.
Update, following the discussion in the comments:
This is a photo of a zucchini plant, note the difference between the male (marked blue, just a thin long stem) and female (marked red, with a “baby fruit” between stem and petals) flowers. The same principle applies to the related cucumber/gherkin plants.