[AnneB]

Went to harvest some more carrots this evening, only to find that they are now infested with carrot root fly.  This time last week they looked and were very healthy.  Now full of flies, yet they have been under fleece all the time.  I just give up.

[Ice]

Don't give up, just try to work out how they might have breached your defences. 

[Ian_A]

fleece is very flimsy and rots very easily. Mesh is much sturdier and conducive to total success - get some for next year. It will last for years and you won't regret it. But I do understand your upset after having similar years ago before I discovered enviromesh