Tips for getting rid of carrot fly

[Emily Peagram]

Hello everyone,

What are your best tips and tricks for getting rid of carrot fly on your plot?

Please note that answers may be edited and used in the May issue of Grow Your Own magazine.

Thanks Emily

[Aberdeenplotter]

First of all you must ignore the myths. Using raised beds does not work to avoid damage from carrot fly. Even exhibition growers using 4ft high barrels have their carrot roots damaged if they do not use barrier protection such as fleece or environmesh.
Putting mirrors between the rows doesn’t make the fly think it has a competitor for its territory and cause it to bash itself to death fighting it’s own image.
Realise that resistant varieties are not totally immune to damage.
Use a barrier such as environmesh or fleece to protect the crop at all times and only remove it to weed or thin out the plants replacing the barrier immediately afterwards. It can also help to spray the crop with a solution of crushed garlic in water as the pungent odour helps disguise the smell of the carrots. Remove any carrot thinning from site.

[Martin H]

Use a carrot fly maggot from a previous infected crop to create an agrohomeopathic remedy. By baking, tituration and potentization of the maggot you can easily create 100,000 litres of carrot fly repellent remedy. Water your carrots with this as the seedlings emerge and again whenever the soil is disturbed by weeding, thinning or harvesting. The carrot flies will ignore your treated carrots and fly on to attack an untreated plant further away.

Alternatively, use a barrier of fine mesh netting throughout the growing season to keep the flies away from your precious crop.

[Lumpy]

I use a belt and braces approach.
I grow in planters, covered with fleece and try and grow spring onions, bulb onions, leeks or chives etc around them.
I like the tip about the garlic infused water so will give it a go this year.

[sparrow100]

I grow mine in tubs on a 3rd floor balcony. Nary a fly makes it up there.

[Bill HH]

I agree with Aberdeen plotter, the thing with all the myths is that some areas are relativly free from carrot fly and people can easily put there lack of damage down to their little tricks when in fact they wouldn't have had a problem in the first place. A carefully constructed mesh barrier is in my opinion the only way. If you suffer regularly do not grow carrots in the same soil each year and if things are very bad I would advise giving up growing carrots for a couple of years to give time for any eggs to hatch and move on.

[skeggijon]

I find growing carrots in a 4ft by 3 ft dolav with rows of spring onions grown between them and fleece covering does the trick. It may be belt and braces, but who wants to spend the season growing, only to find the blighters have beaten you.

[Penellype]

I had a lot of success with the barrier approach at my previous house:
Year 1 whole packet of seed planted in rows in sandy soil. Lovely big carrots but totally fly infested, only one half of one carrot edible.
Year 2 same garden, same type of soil, different bed - 3ft high plastic sheeting nailed to wooden posts around the bed, no top. Lovely carrots, no fly damage.

I also tried the variety "Flyaway" without the barrier - the carrots were less damaged than the previous year but still significantly so. Tasted much less nice than the Autumn King and Nantes varieties grown in the plastic pen.

I don't have room for plastic pens here so I grow carrots in pots.
Years 1 & 2 - carrots grown in old water butt with the soil a good 6 inches below the rim. Nice carrots, no fly damage at all. 2nd year carrots were less big and I decided to rest the water butt soil.
Year 3 - carrots grown in 18 inch pot with soil 3 inches below surface (pots are 13 inches high). Lovely carrots but significant fly damage.
Years 4+ carrots grown in similar 18" pots under veggiemesh - almost no fly damage.

[Alison]

Cover in fine mesh (enviromesh) from sowing to harvesting and you get nice clean carrots

[beeterforit]

A mystery to me is that most experts tell us that these flies can only fly 2ft in height
My veg plot has 6ft fence all around so how do they get in ?
Ladders or a tunnel any body know

[Penellype]

A mystery to me is that most experts tell us that these flies can only fly 2ft in height
My veg plot has 6ft fence all around so how do they get in ?
Ladders or a tunnel any body know

I think the flies can get carried upwards as air flows over fences etc, and then come down again the other side. My plastic pens were long and narrow (for access when weeding etc) so any flies that went up one side would probably have gone right over the pen. A whole veg plot is different in that respect.

[Alison]

I think the flies can get carried upwards as air flows over fences etc, and then come down again the other side. My plastic pens were long and narrow (for access when weeding etc) so any flies that went up one side would probably have gone right over the pen. A whole veg plot is different in that respect.

And some areas just have more of them than others.

[Penellype]

And some areas just have more of them than others.

Indeed, but my old garden was infested with them and the barriers did work. I think I have fewer of them here, but still enough to cause considerable damage to unprotected crops.

[maverick451]

I watched an allotment special and one tip I picked up was to earth up carrot as they come through to beat the 1st round of carrot fly

[Veggiemama]

If they have overwintered in the soil, how do you then get rid of them?
Is it a matter of not growing carrots in that particular bed? Do they overwinter in any soil you have in the garden?

Are there any products you can get to kill them off like nematodes or something similar?
I had them at the end of the year last year and would like to still grow carrots in this bed. I did have fleece on the bed to begin with, but when this did blow off, i never fixed it back in place (silly me)

So, apart from preventing them, how do you get rid of them once you have them?
Thanking you in advance
veggiemama