Im all new to this gardening but am really enjoying being outside in the peace and quiet and learning lots of new things. I’ve was going to deadhead some of the lupins and noticed the top parts are all completely covered in greenfly. When watering my dahlias and nasturtiums I noticed that they are covered in black fly. They are completely different ends of the garden. What I am I doing wrong, should I be doing anything to the plants in my garden as a preventative measure or is it just a case of spraying the plants when I spot any green/ black fly. Feeling really disheartened at the moment as also been trying to grow some vegetables but had problems as they were attacked by spider mites. I understand that there are going to be these pests in the garden but if anyone could offer advice or tips of what I could do to prevent/ minimize these problems would be appreciated so that my plants are much healthier .