[Eblana]

I have lost all my carrots for the past two years to carrot root fly, despite them being grown in raised beds.  I have just bought a packet of environmesh and I am just wondering should I put it over the top of the seeds when I plant them or should I just put it all around the edge of the raised bed?

[simonwatson]

Carrot flies lay their eggs around the carrots, so you want the enviromesh to be off the soil completely.

[JayG]

Using the enviromesh to produce a vertical barrier of 2' or so round the carrot bed still requires a certain amount of luck, partly because carrot flies are such weak fliers (they can get blown over the barrier by the breeze.)

Completely covering them does not require any luck (other than when weeding  ), although it must be securely pegged down all round because the little s o d's can still walk even if they're not exactly peregrine falcons in the aviation department! 

[AndyArch]

Is netting the only way to reduce carrot fly or can you plant them just in a raised bed (approx. 18 inches high)?

[Hampshire Hog]

Sorry Andy I don't think that would be high enough to deter a determined carrot fly. As JayG says they could still arrive with a gust of wind.

Cheers HH

[BabbyAnn]

Is netting the only way to reduce carrot fly or can you plant them just in a raised bed (approx. 18 inches high)?

I think JayG answered your question - whether the vertical barrier is a 2' wall or netting, the risk is that they may get blown over by the wind and land on the bed where they can walk/fly to the carrots

Using the enviromesh to produce a vertical barrier of 2' or so round the carrot bed still requires a certain amount of luck, partly because carrot flies are such weak fliers (they can get blown over the barrier by the breeze.)

Completely covering them does not require any luck (other than when weeding  ), although it must be securely pegged down all round because the little s o d's can still walk even if they're not exactly peregrine falcons in the aviation department! 

A few years ago I acquired some 18"-24" diameter heavy duty plastic tube offcuts from a building site and decided to use them for planting strawberries and herbs.  They are roughly in the range of 2-4 feet tall.  Last year I used one to grow carrots and for the first time, were completely carrot fly free and perfect.  I suspect the reason is that even if a fly manages to get blown over the height normally to keep them out, the chances of landing on the smaller soil surface area is lower.  And the number of carrots out of that pot was equivalent to the row I would have sowed at ground level.

[colin120]

Sow them so you don't have to thin them out, takes a while to sow individually spaced out but saves getting carrot fly, I have done this for the last to years and never had a problem. 

[AnneB]

The only way I avoid carrot fly is to use enviromesh supported on blue plastic pipes and securely fastened down.  I used tent pegs for this for the last two years. I try and sow thinly and don't thin them either. 

This year OH has added some extra wooden supports at each corner of a double height raised bed and I will support the enviromesh on that.

I have tried just a tall barrier,  and it didn't work.  I also tried a tall barrier and no thinning, didn't work either.

[archibtbm]

Our site is exposed so vertical barriers fail on carrot fly.  I grow carrots outside in a raised bed with environmesh over small hoops with the edges of the mesh buried in the soil.  I also grew some in large containers in the GH 

[Eblana]

Thanks folks - I have some hoops and tent pegs in the shed somewhere will dig them out and use them with the enviro mesh.

[Kristen]

Is netting the only way to reduce carrot fly or can you plant them just in a raised bed (approx. 18 inches high)?

The problem, as I see it, is that even just one or two carrot fly getting past whatever deterrent you use will still cause enough damage as to be annoying, particularly after putting time, energy love and devotion into growing the crop

So, for me, the only solution is total exclusion. I'm no longer interested or will even remotely consider a "wall only" solution, companion planting, raising container higher up, etc.  Even if any of those are 99% effective that's still not good enough for me, the 1% cause enough damage to be very depressing, plus I then help establish a local community of over wintering Carrot Fly for next season

[Bohobumble]

also, don't sow carrot seed into beds with soil that has had carrot fly in recently - try to keep a crop rotation going.

[compostqueen]

I disguise my carrots by sowing them with spring onions, just mix the two packets.  Some nigella in there looks well too.