I've been trying to grow mixed lettuce/salad leaves in my conservatory. The results are a bit pathetic. The photo below is about as good as they ever get (in fact recently they've been more like the container on the left rather than the right) - I have a couple of pots that produced a few leaves and have stayed pretty much the same for about three weeks. And if they do progress, all they do is bolt.
Some have been in Durston's peat-free multipurpose compost, some in my own compost from the compost bin - the only difference is that the pots with homemade compost also produce a few nettle/tomato/assorted weed seedlings as well The conservatory is east facing but because of the trees at the end of the garden that you can see in the photo doesn't get a vast amount of light. It doesn't get overly hot, though obviously it's been warm of late, particularly as we've been closing it off to keep the house cooler. But they were pathetic before the really hot spell too.
I've not been feeding them, beyond a splash of Baby Bio when I've been doing the houseplants, but I'd have thought the compost would have at least enough nutrients to get them past this stage.
Any suggestions as to cause and remedy, please? I try to grow my own really just to reduce plastic use but it's quite possible there's more plastic from the bags the compost comes in than the amount I'd save by not buying bags of mixed leaves.
BTW, I've tried growing them outside in the past but between the slugs and the leaf miners they've been even less successful.