On Wed, 28 Jan 2009 00:22:43 +0000, Paul
wrote:

In message , Jim S
writes
What's the current 'green' way of controlling carrot fly.
I used to use spring onion thinnings left around to mask the smell, but my
friend says that does not work for him.
I have suggested inter-cropping with onion and not sowing so close that
carrot thinning is unnecessary.
I have heard tales of low walls around (wood or fabric) as CF fly very low.
Howver he has bee told to use 12" raised beds for the same reason.
This seems excessive and doesn't the wind carry the flies?

After 3 successive years of deformed and holed carrots ( heavy London
clay soil and stony with flint ), last year we grew some in an old metal
dustbin with soil/compost up to about 6 inches below the rim. We got
long straight clean beautiful carrots.

Yes, that is partly becuase you used good soil, and because carrot fly
don't fly up in the air. They skim the ground. Putting a barrier of
fleece, plastic etc up to about 18 inches will stop the fly finding
the carrots. your dustbin served the same purpose.
An allotment neighbour last year cut a plastic barrel in half, filled
each half with good compost and grew some excellent carrots

Pam in Bristol