I've tried growing potatoes for the first time this year in planters. I've still had no sign of flowers and the foliage (which looked great for ages) now looks weak and lots of leaves have come off. I've been plagued with snails and slugs which I regularly clear. They've been regularly watered and are in a sunny position that has shade from late afternoon.They were planted in a vegetable compost recommended by the garden centre. I followed all the planting instrucions with the planters and if I get no crop this year I'd really like to not give up and have a go next year. Can anyone help with some encouragement and advice?