How to Protect Carrots from Carrot Fly

So what bugs eat carrots?  The answer is carrot flies.  You might think it is too early to think about carrot fly.  However, there is a lot you can do at the planting stage to ensure you get a healthy crop.  So well worth reading this now before you sow. With other veg you can wait until they are ready to fruit to use plant protection.  Carrots need neeting at an earlier stage and its no ordinary netting as carrot flies are tiny!

If you have yet to experience that awful sinking feeling of lifting carrot after carrot riddled with dark crevices, tunnelled out by the dreaded carrot fly larvae, then consider yourself lucky. But for those of you that have, fear not! Haxnicks have been fighting various garden pests for over 20 years, and have picked up a few tricks along the way...

 

How to protect your Carrots from Carrot Fly with Haxnicks
Image courtesy of www.morguefile.com

But first... some facts about carrot fly:

  • So where do carrot flies live? They live in bushes, hedges, trees and thrive on allotemnts where members of the carrot family are planted close together year after year.
  • Carrot fly also affects other vegetables in the parsley family, such as Parsnip, Celery, Dill, Coriander, Fennel and Celeriac
  • They are attracted to the smell of bruised foliage
  • The larvae that damage the roots can continue to feed through the autumn into winter, moving between plants
  • The adult carrot fly is approximately 9mm long.  It is a slender, metallic, greenish-black fly with yellow legs and head. Larvae are creamy white, tapering maggots

How can you tell if your carrots are infected? - Check for reddening of the foliage and stunted growth

So now we know a little bit about the pest itself, we can look at some of the ways which we can protect our crops from infestations:

  1.  Make sure to avoid using previously infested ground. Carrot fly larvae are capable of surviving through the winter.  So rotate your crops and avoid re-sowing any vegetable from the Parsley family (see above)
  2. Sow later to avoid sowing during the main egg-laying periods, which are (for most parts of the UK): mid-April to the end of May & Mid-July to the end of August.
  3. Sow disease and pest resistant varieties such as Fly Away F1 and Resistafly F1, available from garden centres and online seed suppliers.
  4. Erect a fine-mesh barrier at the time of sowing.  the imprtant factor here is How high do carrot flies fly?  And the answer is only around 40cm so a barrier at least 70cm high should do the trick. Check out our Micromesh Pest & Wind Barrier which will work for containers and open ground.  Or a Micromesh Tunnel - with 0.6mm netting it will keep the Carrot Fly from getting to your precious crop.
  5. Sow thinly so as to avoid ‘thinning out’, releasing the smell of bruised foliage
  6. Thin out or harvest on a dry evening with no wind – or use scissors so that no bruising of foliage occurs
  7. Try companion planting - we have been asked do marigolds deter carrot flyy.  the answer is Yes!  Growing varieties of pungent Rosemary, Alliums, Sage or Marigold provides a deterrent/’smokescreen’
  8. Grow your carrots in a tall planters - for example the Haxnicks Oxford fabric planter or Carrot Patio Planters
  9. Lift main carrot crops by Winter, especially if any are infected – don’t leave them in the ground to serve as food for overwintering larvae.

Thinning out tip: Use scissors to avoid bruising the foliage (and releasing the carrot-fly attracting scent)

To find out more about carrot fly, and the other pests that may arrive in your garden check out Pippa Greenwood's excellent RHS book for plant by plant advice on Pests and Diseases

Have you any experience of carrot fly damage? What do you think went wrong? Please let us know your thoughts using the comments section below.

 

FAQs on Growing carrots

Can I eat carrots that have had carrot fly?  The answer is yes but you may not find them to be worth the effort.  They will be full of holes which you can cut away but you may find they are more hole than carrot!

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