[fatbelly]

Hi All,
I have sowed a late crop of Autumn King Carrots under enviromesh. The seeds have now germinated and about an inch high. Unfortunately the weeds are growing as well. When is it best to lift the mesh to get weeding, I would be quick as possible because I don't want my crops ruined as has happened in the past.

Thanks

[DD.]

First thing in the morning. They are most active late afternoon to early evening.

[fatbelly]

Right thanks DD.
I will get down the plot early Saturday left the mesh, weed quick as I can & then get the mesh back in place.

In the past i have just not lifted the mesh and put up with the weeds but this year I have decided to give one good weeding cover over again & then leave well alone.

Is there a time in the autumn or winter when I can leave the mesh off permanently?

[Goosegirl]

Though I have never been successful growing carrots, I have wondered if some crushed or torn mint leaves spread alongside the rows would deter the carrot fly.

[fatbelly]

What I don't understand is how do commercial growers produce tons and tons of fly free Carrots!
What is their secret and why can't we use whatever they do?

[BabbyAnn]

What I don't understand is how do commercial growers produce tons and tons of fly free Carrots!
What is their secret and why can't we use whatever they do?

pesticide - which is why it is always a good idea when cooking to top and tail carrots bought from the supermarket as that is where contaminants can accumulate

[JayG]

Assured Produce Crop Specific Protocol: CARROTS is a link to a PDF file showing what was approved for commercial carrot growers in 2006 (it was still being quoted in 2015 so presumably is still valid.)

Not suggesting all farmers use all of them, but it's quite a long list of insecticides, most with a 'toxic' rating, and that's before you get on to permitted herbicides! 

[fatbelly]

First thing in the morning. They are most active late afternoon to early evening.

Hi DD,
I did as you said and went down the plot first thing in the morning, however Ive just been searching on the Moles Seeds website and it states the following

'It is best to thin [Carrot] seedlings in the evening when carrot fly are not around, as it’s the odour of bruised leaves which attracts them.'

[Salmo]

I weed mine at dusk or when windy. I doubt if many carrot flies are going to arrive in the 20 minutes or so that you have them uncovered anyway. I also always water them after weeding /thinning to kill the scent. Right or wrong? Never seen a carrot fly hanging about so who knows.

JayG's Assured Produce document is good reading. If you read nothing else read pages 13 and 14 where it sets out how farmers should avoid carrot fly by non-chemical means.

The general principle of large exposed fields and wide separation from last years crops are not within our reach but there are some things we can learn.

The same principle applies to other large scale crops such as peas. If a farmer sprays a large field for pea moth he is likely to kill all the adult moths in the middle of a 20 acre field while you or me on our ten foot row are unlikely to kill any.