When to cover up?

Will you please advise when I should put on and take off the fine mesh I purchased for protection of brassicas (white fly, cabbage white butterfly) and carrots (carrot root fly) I live in Somerset.

Thank you

Michael   

Cabbage whitefly can be active well into winter and sometimes through the winter, so if you have mesh over for that pest, I would suggest leaving. For Cabbage white butterfly we are approaching a time when no more eggs are being laid but I would suggest keeping protection over until the first frosts and the same for Carrot root fly. Hope this helps.

Regards,

Julian Ives