Tell me about greenfly (& how to eliminate them)

Little green bastards !

My “garden” consists of flower pots on the ground and hanging from window railings. I’ve got greenfly. On Hydrangea/hortensia, fuschia, lily (ivy, daffodils, tulips, and small conifer unaffected) … how can I get rid of the green things ?

I’ve tried an organic spray (which frankly smells not unlike the washing up liquid I’d use in an emergency) but that doesn’t seem to have worked.

Any ideas ?

How can I prevent re-infestation - do they lay eggs in the soil or something ? Why do they keep coming back ? Could I be bringing them in on new plants ?

(I’m hoping for a factual answer which is why I plumped for GQ but …)

I am no gardner – indeed, I am the anti-gardner – but I remember my grandmother collecting a few cigarette butts in water and letting that steep overnight, then spraying the plants. Her explanation was that nicotine from the cigarettes was fatal the the little bastards.

She always had a healthy garden, so I assume she knew of whence she spoke.

Another way for potted plants is to bag 'em overnight. Put each plant in a trash bag, and put a cotton ball or two soaked in ammonia next to the pot. The plant won’t mind the vapor, but the bugs can’t handle it. Yes, you may have to repeat in a week or two when the eggs in the soil hatch.

Take the bags off before full sun, though, or you’ll cook the plants.