What is destroying my oriental chives?
I'm hoping someone will know what is destroying my oriental chives. They are covered in tiny black stuff that are similar to aphids and the chives have lost vigour and gone yellow.
I must say it happened last year, so I turned the pot out and carefully removed all traces of the black stuff and re-potted in fresh compost in a cleaned out (different) pot. It grew well during the summer but it is now subject to the same fate as last year. I have other pots nearby but these are the only ones suffering. Does anyone know what these pests are and how to deal with them?