Ways to gently give carrot fly the chop

How can I control carrot fly in my garden? – Fraser Henderson, via email DAIVD: Carrot flies are drawn to oils that are released when carrot leaves are bruised or broken, so try to avoid handling them. Be careful when sowing so that you don’t have to do any thinning, if possible. Otherwise, use a physical barrier, such as a horticultural fleece.