carrot flies?

Hartley Botanic · Feb 11, 2010

I've just read a tip and I am wondering if it makes any sense to anyone else.

"Grow carrots in tubs with high sides, so that they are above the height at which carrot flies typically travel."

Seriously, would this work...?! :cnfs:

Alice · Feb 12, 2010

Hi hartley, I don't know if it's true but it's said that carrot fly can't get more than 18" off the ground.
All I know is if I plant carrots in the ground they are totally ruined by the fly.
I grow some carrots in tubs - raised up - and they are fine. So maybe it's true.

wiseowl · Feb 12, 2010

Hi Hartley I have always grow my carrots in raised beds and tubs,As our little friends the Carrot flies can,t get above 30 inches.Hope this is of some help.Or failing that you could always try companion planting,Onions are good planted in between the Carrots,its the aroma of them,stops the carrot flies from smelling the carrots scent.

misterroy · Feb 12, 2010

old wives tales, buy some mesh.

The flys are tiny, they are going to go where a gust of wind takes them. My neighbour has a two foot high protective fence, and carrotfly

Lovage · Feb 12, 2010

wiseoldowl said:
Or failing that you could always try companion planting,Onions are good planted in between the Carrots,its the aroma of them,stops the carrot flies from smelling the carrots scent.
Click to expand...

This idea has been around for ages and is repeated and quoted in many books but as far as I know it does not work!
I have never met anyone for whom it worked and I have heard of trials which failed to find any benefit.
Does it really work for you Wiseoldowl?????

wiseowl · Feb 12, 2010

Hi Lovage,With respect Indeed It does I am not in the Habit of giving sound advice which I haven't tried first,I continually grow my carrots in Black plastic dustbins and have done for a very long time
When I give my opinion or advice 99% of the Time it comes from the way I grow vegetables and Roses,not from Books or other sources,if I haven't had first hand knowledge or don,t know something I will always say, as for old wives tales it is My honest opinion,that we can still learn a lot from them,I never dismiss anything until I have either seen it tried or tried it myself,I also believe that dismissing anything without trying it (especially in gardening) is a sure way of not learning anything new.

theplantman · Feb 12, 2010

as far as i know the carrot root fly normally looks for just above ground level. (I grow my carrots in raised beds with 18inch sides) However at mateing time they operate at higher levels so can find carrots in pots or raised beds. Carrot mesh or net curtains are fool proof and pretty 100% sure to keepp them out, for the last few years the raised bed has been enough for me.

Oh yes they are most previlant on sunny evenings in may and june (there are some about all summer) so dont touch or thin your carrots then that will send out the scent and alert the pesky critters.

Hartley Botanic · Feb 13, 2010

Well there you go, I never knew this. To be fair I am not a hugely enthusiastic edibles gardener (yet? my Dad is so there's a little experience/hope there!) but this is definitely helpful info :thumb:

I hope that the onion 'companion planting' works. I love the idea of such a thing and was just discussing a similar gardener-plant-plant relationship on another board; the use of marigolds in greenhouses to keep whitefly away from tomatoes!

misterroy · Feb 13, 2010

Carrot Fly= Carrot+flying+Carrot fly of opposite sex
plant some carrots next year in your tubs, and plant the same amount in the open ground on their own and then some with onions. Then see if you can learn something.

You might find none are infected, you might find they all are. You might not be growing enough to attract carrot-fly in the first place.

My neighbour had not had carrotfly until the last few years, I reckon they are attracted by my 20000 carrots, cant get to them, fly over to his 8 foot row, get down an dirty, then lay eggs.

wiseowl · Feb 13, 2010

Hi Misterroy I shall certainly plant my carrots in tubs as I do every year and continue to grow some in open ground as usual and if you have the time and can teach me about our tiny orange friends the Carrot, I am always willing to learn from someone such as yourself ,Thank you for your kind and generous offer

madfoxdog · Feb 13, 2010

My grandad always used to grow his carrots in tubs and it seemed to work for him.

Marley Farley · Feb 14, 2010

I tried all sorts ove the years, in open ground & I too have found best results are from tubs or raised beds... I even sprinkled Wood & then coal ashes on the row after planting as I was told that is supposed to help, but sadly found no difference in the end... So I grow mine raised up in tubs etc now.... :wink:

Hartley Botanic · Feb 14, 2010

misterroy said:
My neighbour had not had carrotfly until the last few years, I reckon they are attracted by my 20000 carrots, cant get to them, fly over to his 8 foot row, get down an dirty, then lay eggs.
Click to expand...

Haha. Your poor neighbour but hehe, that made me giggle :lollol:

Marley Farley · Feb 14, 2010

Found this interesting little tit bit at the Carrot Museum...:wink: Seems we are all doing something right on the whole but it is just a total battle.. Going to sow earlier if I can this year & see...

Dealing with Pest No 1 - The Carrot Fly The carrot fly, Psila rosae is a serious and widespread pest and is really the only pest worth worrying about. The damage is done by the grubs tunnelling into carrot roots, disfiguring them and allowing moulds to gain a hold.

How do you know you have a Carrot Fly attack? Basically you will not know until you lift the crop. In severe infestations the first sign is that the Carrot leaves look an orange, reddish, rusty colour. They then turn yellow. On lifting an affected Carrot it will be seen that the root end will be black or dark. Close examination of what appear to be good Carrots may reveal small holes in the Carrot. If Carrots are put in a bucket of water badly affected ones will come to the surface. This however does not mean that those which do not float are totally unaffected.

Covering the crop with Enviromesh or similar is the best method of fly control. The carrot fly locates its carrots by scent. Crushing the foliage may make them easier to find so leave them alone! If you must weed the carrots, do it on a dry evening with no wind, as the scent of the bruised foliage will not spread so far, and carrot flies take wing in bright sunlight. Pull carrots for eating in the evenings too, for the same reason.

You will often see the suggestion that growing onions in between the carrots keeps the carrot fly at bay. The idea is that the onion smell fools the female fly, which is otherwise attracted by the lingering foliage scent after carrot thinning. Alas this lovely romantic idea rarely works in practice. Onions can only be effective when the onions are in active leaf growth. Best results come from four rows of onions for every one of carrots and the beneficial effects will diminish as the onions start to bulb.
Other strongly scented plants such as French or African marigolds, pennyroyal and garlic have all been suggested in the past, but have insufficient data to back up their claims. Mix carrot seed in with a packet of mixed annuals and sow as usual. A mixed crop should sustain less damage than a monocrop.

You can also emulate commercial organic growers method of timing your sowings to miss the egg laying season. This means sowing in February or early March, or waiting until Mid June.

Mulching with grass cuttings can make it harder for the female flies to find a suitable egg laying site. The crop appears to benefit from the extra support given by the earth and you'll have noticeably fewer carrots with green shoulders. The mulch enables the carrots to make better use of nutrients and water in the soil, encouraging healthy growing conditions and improving their ability to resist attack. It also makes it more difficult for the female flies to lay their eggs in cracks in the soil. A range of creatures will make their home under the mulch, some of which will be predators of the carrot fly such as ground beetles and centipedes. Watch out for slugs and snails who will also thrive in these conditions!
Location can be vital. However unappealing to the gardener, a windswept site with little protection is ideal. Carrot fly adults are weak fliers and tends to lurk round field edges or garden margins.

A couple of varieties offer some resistance to the problem these are "Fly Away" and "Sytan". If the problem is serious in your area these will probably be attacked with the rest. Best results are obtained if no other variety is grown alongside. Autumn King types are carrot fly's favourites, so avoid sowing these if there is a known problem.

You can also try to reduce this pest by placing a sprig of wormwood around the plants crown. This masks the scent of carrots and the flies should leave them alone. Other plants to try include black salsify (oyster plant), coriander, lettuce, onion family, pennyroyal, rosemary and sage.
How do I detect Carrot Fly?
Basically you will not know until you lift the crop. In severe infestations the first sign is that the Carrot leaves look an orange / reddish / rusty colour. They then turn yellow. On lifting an affected Carrot it will be seen that the root end will be dark or black. Close examination of what appear to be good Carrots may reveal small holes in the Carrot. If Carrots are put in a bucket of water, badly affected ones will come to the surface. This however, does not mean, that those which do not float are totally unaffected.
More Detail on the No 1 Pest:
An adult carrot (or "rust") fly is a very small black fly which has been described as "a low flying miniature cruise missile". The fly is attracted to the Carrots by smell. It lays its eggs in the soil adjacent to the Carrots. The eggs hatch and the grubs burrow into the roots. The result is a mess, with grub tunnels all through the carrot.
It stays in the ground over winter gorging itself on your Carrots, pupates and lays eggs in early spring. Eggs will ideally be laid near to Carrots but Parsley, (and Cow Parsley), Celery and Parsnips, are also affected. After the spring generation have hatched they lay eggs in June and July and this generation hatches and matures in enough time to have another frenzy of egg laying August / September time.
This insect pest also loves parsley, parsnips, celery and celeriac. Attacks are particularly bad in old established gardens where the population builds up each year. Most carrot pests and diseases are soil-borne and can be controlled by crop rotation.
Adult flies, attracted by the smell of carrots, lay their eggs at ground level so the little white grubs can hatch out and tunnel into the carrot roots. Therefore vulnerable young seedlings die and the foliage of large seedlings turn bronzy red and the plants weaken.
There are usually two, sometimes three, generations of carrot fly in a year. The first and worst attack occurs mid-May and mid-June; subsequent attacks are in Autumn and in Winter in mild seasons.
The Carrot Fly is low flying and therefore can be prevented from laying its eggs by physical barriers such as polythene. Surround the carrots with a 60cm high barrier of clear polythene film or fine netting nailed to canes, making sure there are no gaps at ground level. These barriers should be no more than 100cm wide. In dry months water the carrots if they appear to get dry because of the barrier.
The later generation feeds on carrot roots left in the soil in Autumn and early Winter. Grubs pupate in the soil, and hatch out as the first generation next Spring.
Other practical tips include sowing early carrots before mid-March and main crop towards the end of May or mid-June. Sow very thinly to minimise the need for later thinning. You can try growing carrots under fine net film, very similar to mosquito netting, making sure there are no gaps at ground level.
Inter-planting onions or garlic in the carrot beds may also ward off the villainous flies. Mix carrot seed with feathery leaved annual flowers when sowing.
Compost and wood ashes will also scare off not only carrot flies but carrot weevils, wireworms, and other carrot pests. Probably the best organic way to get rid of pests is to soak the bed once a week with a thin mixture of wood ashes and water using a watering can.
Some chemical control can be achieved through dusting the rows before sowing in Spring with bromophos, phroxim or pirimphos-methyl dust. Protection of late crops can be done by spraying with half strength liquid pirimphos-methyl in early August.
Grow varieties with partial resistance. "Fly away" and "Sytan" have some resistance and the old fashioned mainly white fodder carrot is also fairly resistant.
Click to expand...

wiseowl · Feb 14, 2010

[align=center]This is in no way diminishing the Serious problem of Carrot Fly
Just a few quotes
:lollol:On the Light Side:lollol:
Heres a novel way to prevent carrot fly a row of small mirrors surrounding the bed,the carrot fly is territorial, and wont lay eggs if competition is in sight, the fly will continuously attack the mirrors eventually exhausting itself:lollol:
----------------------------------------------------------.

If you suspect that the dreaded fly has got past your defences,your netting and smell diversions,and is living within your carrot fortress.Then Place some bits of mirror along and between your rows of growing plants .The idea is that the female carrot fly will see her own reflection and charge at it knocking herself out:lollol:
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From what I understand, the carrot root fly is silly enough to be confused by ...

the blue colour of Nigella
the smell of dill / garlic / onions / shallots
the presence of a mirror in which to admire itself
a raised bed of more than 2ft:lollol:
I thought it easier therefore to simply put up a sign on the garden gate saying, "No carrots in here mate, try next door". ... in blue letters of course.:lollol:
----------------------------
I planted carrots next to the onions and it didnt work so i pulled them up and hit people over the head with them and gave them to my mum.:hehe:
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carrot flies?

Hartley Botanic Gardener

Alice Gardener

wiseowl Admin Staff Member

misterroy Gardener

Lovage Gardener

wiseowl Admin Staff Member

theplantman Gardener

Hartley Botanic Gardener

misterroy Gardener

wiseowl Admin Staff Member

madfoxdog Apprentice Gardener

Marley Farley Affable Admin! Staff Member

Hartley Botanic Gardener

Marley Farley Affable Admin! Staff Member

wiseowl Admin Staff Member

Problem with my carrots and Lettuces

Carrots and lawn dressing

Carrots Growing

Advice on these carrots please

Pest Cocoon? atop a carrot?

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carrot flies?

Hartley Botanic Gardener

Alice Gardener

wiseowl Admin Staff Member

misterroy Gardener

Lovage Gardener

wiseowl Admin Staff Member

theplantman Gardener

Hartley Botanic Gardener

misterroy Gardener

wiseowl Admin Staff Member

madfoxdog Apprentice Gardener

Marley Farley Affable Admin! Staff Member

Hartley Botanic Gardener

Marley Farley Affable Admin! Staff Member

wiseowl Admin Staff Member

Problem with my carrots and Lettuces

Carrots and lawn dressing

Carrots Growing

Advice on these carrots please

Pest Cocoon? atop a carrot?

Share This Page

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