[casper]

Hi, my husband has put up my greenhouse today, I back onto a field and I am surrounded by trees, I love the trees and wildlife they attract but they are infested with Green fly, Are there any fly traps available or homeade recipes for treating them in my Greenhouse, thank you

[Yorkie]

You can buy yellow sticky paper that you suspend in the greenhouse (I think it's still available!).  Otherwise, the pyrethrum-based sprays are organic, I think, or just water with a very small drop of washing up liquid in it.  If you do use a bought spray, make sure you know what plants it is suitable for and how many max applications