Lemon Trees – Heavy Aphid Attack.
Heavy aphid attack on the the lemon trees I would treat them with a systemic insecticide called Provado by spraying the leaves and watering some into the pots,this is available from most garden centre retailers.Next I would spray with a soft soap spray,this will help break up the black mould substance which is honey dew left by the attacking insects.Finally I would plants some tagettes and marigolds around the lemons to help keep further attacks away.