It sounds like your plants are wilting from the bottom up. This is classic symptom of overwatering. Maybe when you brought them in you blocked the drainage holes. I had that happen to a plant I had in a large pot. I didn't realize I was drowning it until I picked it up and whoosh! If that's the case then there's not a lot you can do except hope the plant recovers.

If it was underwatering, I would expect to see the edges of the plant drop first. Then the plants would recover quickly with a watering. The plants aren't yellow so they're getting enough sunlight.

Too much fertilizer can kill seedlings too. And one last idea: maybe they were exposed to cleaning chemicals, pet urine (cat) or some other toxic agent.

I hope this helps,

Chris

Hello Chris

I am doubtful about whether it was overwatering, as I am pretty careful with the water, having done the drowning thing myself before. They haven't had any extra fertilizer - hadn't considered the cat option, which is a possibility.

Today some of the leaves are looking a bit shrivelled just on the tips, while others are somewhat curled. Overall the plants don't look any worse than they did last night, so maybe they will pick up. I'm a bit hesitant of planting them out if they do have some sort of disease though. I am keeping them separate from the others just in case.

Thank you for your help

Jen