You probably already know this one, but as no one has mentioned yet...
As a general pest deterant, and good liquid feed at the same time:
Fill a bucket half full with nettle tops, then fill bucket full with water.
Add 3 crushed cloves of garlic, stir and cover.
Keep for 3 days, stirring once a day.
Than strain off liquid into watering can, then spray liberally on plants.
Really seemed to work on my lottie re blackfly etc, but then I'm not surprised as this soup stinks to high heaven after 3 days fermenting!