A word of reassurance for my gentle reader, none of the methods I've tried have worked so far.   I've met people whose supreme ambition for 50 years has been to successfully grow one single row of carrots without the ravages of this feeble and weak little fly.

Know your enemy - brief life-history

The fly itself is about a quarter inch long, black-bodied and red-headed, weak fliers with a strong sense of smell - but I've never seen one.   Ah but - the larvae, those I know well.

• The fly emerges after winter hibernation in May, and lays eggs in the nearest carrot row; eggs hatch into larvae, which devour the young carrots - you'll see reddish-tinged leaves, then gaps, and never a carrot.
• The larvae turn into pupae and hatch into a second generation of fly by July - which promptly lay eggs in a new carrot row.   This time the carrots can sustain some damage but are usable if you pick them quickly enough (realistically, though, you will lose a lot of your crop).

Prevention and control

Don't trust just one method - use as many as you can; the most reliable methods in *bold*.   Hmmm, do you really want to trust somebody with my record of failure?

• Barriers?
  • *Growing under enviromesh/fleece.*   Best of all, but sadly we had vandals!   Take care to weed and water properly.
  • Sow between upright wooden frames, covered with polythene or enviromesh, 30 inches high, and no more than 12 inches wide; the top is open.
  • Grow in a cold frame - worked for Brian across the path from me.
  • Fill an old bath with soil and grow in there - the flies go round rather than up to he bath.   Why not, if it works!
• Husbandry?
  • *Choose your time to sow - some suggested dates*
    
    - late May
    - early Feb/March
    - early June
    *- August*
  • *Religiously clear whole rows of carrots as soon as they show signs of carrot fly.*   Don't imagine that only one or two will be affected!
  • Ridge up the carrots at least a couple of times in the season - draw the earth up at least a couple of inches over the carrots.
  • Sow very thinly to avoid thinning and attracting the fly.   (Try mixing seed with sand, or wallpaper paste (fungicide free) to make this easier?)
  • Sowing coated seeds - hmm, didn't work for me.
• Varieties?
  • Choose resistant varieties?   According to Kitchen Magazine's tests, Parabel and Yellowstone were highly resistant; and Cubic and Fly Away showed some resistance.
  • Complement resistant varieties with others to divert them?   Autumn King is apparently the flies favourite
• Companion Planting?
  • Sowing with annuals - the idea is to mix carrot seed 50:50 with four or five annuals, preferably with feathery foliage.   Sow them altogether, or in close rows, alternating carrot and flower.   According to Joy Larkcom this confuses or deters the fly - she suggests Love-in-a-Mist (Nigella damascena), Blue Flax (Linum usitatissimum), cornflower ((Centaurea cyanus), godetia, nemesia and scabious (Knautia arvensis).   Worth a try - at least it will look good!
  • Mixing with Tagetes (French Marigolds).   Another idea to confuse or deter the fly.
  • Growing Salsify alongside; according to an old book in the local library, salsify repels carrot fly - but there's no indication whether it's the plant in its first year, or in its second flowering year.
  • Sowing in between rows of onions - didsn't work for me, even following the advice that you need four rows of onions to one row of carrots.
• Occasional watering with heavily diluted Jeyes Fluid seemed to have some deterrent effect.   I pulled some baby carrots - but what else were we eating, though?

Or I could of course simply give up, and accept that an allotment is a daft place to grow carrots.   But I at the plot exactly half-way between my two half-plots, where Karl used to grow beautiful carrots *by taking no precautions!*

The only thing I could think of is that his carrots are a little more open and exposed than mine.   Carrot fly can smell a crop from seven miles away, apparently.   I guess they sail in on the prevailing wind, and overfly Karl's bed at some speed.   Rather than beat their way back up-wind to get his carrots, they carry on gently to the next "station", the more sheltered carrot beds - mine!

If you have any other ideas, let me know please - use the Guest Book link above.