my lillies leaves started to curl up and have dark green stripes on the leaves and look quite weary, they did this last year so I changed the compost hoping that would help, this year they had green fly on but I managed to get rid of them, what is wrong with them. thanks
Have you seen any of these?
http://www.rhs.org.uk/advice/Profile?pid=553
(NB: You're not necessarily looking for anything bright red. Read the bit about their excrement-coated grubs, which you might more easily miss).