Just popped this tip online: www.growingbonsai.net/aphids-how-to-reduce-their-impact/

The best non insecticide is washing up liquid in a weak solution which is very effective, needs doing frequently. I don't like to use any insecticide on any plants in my garden, they do too much harm.

Just looked at this link - thanks for posting. I do sometimes get ants in my kitchen, a proven deterrent is to wipe a clove of garlic across the doorstep, I understand they also hate the smell of mint, rosemary and many other strong flavoured herbs so an alternative to the water barrier may be just to rub the pots with something scented and repeat every week or so. Incidentally, garlic is so easy to grow, haven't bought any for quite a few years, just keep a few bulbs from each crop for splitting and replanting

Dave