Will the greenflies completely ruin my summer in the garden? Do they stay until the weather gets cold again? Neighbours tall tree at the end of my relatively short garden is completely infested with greenfly. Neighbour has a long garden so is probably oblivious to the problem. Tree is taller than the house. The little buggers blow off the leaves all over my washing, all over me and are now making it in through the back door. Im sick of them and its only May. If you see any hungry ladybirds point them in the direction of Herts please!