[mellowmick]

Given that carrot fly cannot reach more than a height of 20', (unless it gets a fortunate lift from a gust of wind!)

I heard 30', which is why the blue bins were meant to be good (it was featured on the allotment TV show which no-one saw cos it was broadcast on Sunday mornings when everyone was.....at their allotments).
Picked one of those low shell-style sinks up at the plot skip and it now hosts my lemon-balm, which is thriving.

Funny; no jokes about 'tap roots' yet. :roll:

[John]

I've seen NVS growers with a bottomless bin stacked onto another one, filled with sandy compost mix etc and they grow those huge long carrots in them. Not so much the fly as providing the perfect condition for them.

Personally, I'm looking for the perfect taste!

[GrannieAnnie]

I'd prefer nice taste to long roots too!!!!!

[mrskp]

shhhhhhh don't tell them, they might hear what our plans are and go a bit higher.

 

[GrannieAnnie]

You're right, they might get a longer ladder!!!!!    

[DD.]

I heard 30', which is why the blue bins were meant to be good

The RHS recommend a barrier of just 24'.

http://www.rhs.org.uk/advice/profiles0500/carrot.asp

If it's good enough for them............!

Certainly worked fine for me this year,

[mellowmick]

I can imagine Carrot Flies pegging out, like so many insect Mallorys, as they tackle the cruicial last few inches, low on oxygen, roped together, struggling for a grip on the unyielding blue plastic....

[muntjac]

frost on thier noses. # do flies have noses?

[philsmith1967]

I grow carrots and parsnips for showing (two 1sts again this year!), I grow them in 3foot high drainpipes which are 4" in diameter. I have never had trouble with fly and can only assume that this is because they are said to be low flying. I had trouble with them on the allotment last year but they were ground grown for the kitchen.

[GrannieAnnie]

How many bits of drainpipe do you use Phil??