[Plantoid]

Having returned from holiday to find things a wee bit overgrown ( hoW I hate seven weeks of holiday abroad  ) it took me a few days to get the raised beds back under control ..i then started to plant thing out .
 Now 3 weeks later I noticed that some of the transplanted cabbages were dropped over to one side and had a yellow tinged leaf or two low down .
 on pulling up the affected plants sure enough  the white maggot shaped 15 mm long lava of the cabbage root fly was ther e munching the stem of the cabbage some 8  mm below the soil line.


NOTE EDITED  from 15 mm to 8 mm  long  trust a guy to get his size wrong!

I know I can get a bio control called Nemasys Grow Your own ( £5 a punt for 60 sq mtrs control ) that will zapp the blighters and numerous other spiteful critters that attack brassicas and other root crops
Have any of you used it .. if so was it any good ?.


 Are there any " Grandads "   solutions out there to the prob that are still easily available  beside putting a fly collar around each plant at transplanting time.

[Fleecewife]

Seven weeks holiday??  Lucky you 

Your maggoty things don't sound like cabbage root fly as they are too big, although the other symptoms fit.  Any cabbage root fly maggots I have picked out have been less than about 5mm long then they turn into a dark red crysalis.  Maybe you just have monster cabbage root flies where you live 

[Plantoid]

          I've edited my post as you are correct FW

[Fleecewife]

 

I have never found those collars to be useful and they seem to damage the stems of young plants. I have tried squares of carpet underlay too and found they didn't help and then disintegrated so I couldn't get them off the soil.   
I lose some plants every year to cabbage root fly so I'm hoping you get some good replies.  I have tried laying a mulch of sheeps fleece around each plant but it had zero success.  I now grow my brassicas through a weed suppressing fabric and that does seem to be having some effect although I'm not sure why - the hole round each plant is quite big so no physical barrier to egg laying. I wonder if it's to do with so much of the soil being covered that the flies avoid it?
I start my plants off in pots in the polytunnel but even that isn't failsafe as I have seen the little beggars amongst the roots even before I have planted them out.  Other than squashing the ones I can see at that point I don't know how to get rid of them once they have colonised - it would be lovely to have an answer.

[Skirza]

We got cabbage root fly on every one of our cabbage/sprout plants (120 of them). We managed to save the plants to a degree by digging each one up and knocking off the maggots, then we planted them in fresh compost and covered them with fleece cloches.  Most of the plants have semi recovered and we did manage to pick 4 cauliflowers earlier in the month. Most of the sprout plants are stunted (can still eat the tops tho) There are 3 lots of egg laying apparently, the 1st wave is around the time the cow parsley starts to flower. The only failsafe way of keeping the flies off the plants is to form a barrier. Believe me, next year the whole lot is being covered with mesh!! 

[clumbaboy]

Hi All
     This a tip for cabbage root fly that I use and my father uses, when dibbing the holes for your brassicas put a puff of ant powder down the hole stops em every time, not much good if you are organic though, I'm not so anything goes. 

[Plantoid]

That sound like it has legs and can run Skirza , I will keep it in mind ..any special type of ant powder ?

 Meanwhile I have ordered some of the " Nemasys grow your own "  nematode bio control  stuff.
The big rub is that it is temperature sensitive and has a short shelf life as well as requiring to be refrigerated till ready for use.

Looking around the beds this afternoon  , there are six more visable casualties .. at this rate I'll lose all 140 brassicas  in four weeks or so.

[clumbaboy]

Hi,

  I just use the cheap normal ant powder available from garden centres, supermarkets and wilkinsons (other stores are available). Give a good squirt down the dibbed hole when you plant them. Not sure if you will be able to lift your brassicas now and do it. 

[Plantoid]

Many thanks ..i'm off to buy some tomorrow .

I should be able to lift them ( the bigger ones already transplanted , if this forcast rain drops down.

 I also have some very late greens , started off in  the glass house 10 days or so ago in one inch high sections of square down pipe 3 x 3 " set upon a bed of quality sterile compost .

I've slid a kiddies sand spade under the open ended pots and lifted the seedlings up on a pile of earth  to then plant them outside in the main beds to grow on and develop the secondary leaves  ( They are just peeking out )  .


 If the expected frosts hang back for another ten days I should be able to get them all transplanted out in dusted holes ..

[Fleecewife]

Don't forget to report back on how your experiment works

[Skirza]

Just one thing....cabbage root fly eggs are laid in 3 cycles...the 1st in may (early June in the far north), second in June/july and 3rd in August/September. Any plants put out now in fresh soil should by all rights be safe so you shouldn't need to dust unless you really want to. 

[Plantoid]

The Nemasys grow your own  arrived today .. cost £4.99 & £2 P&P ... it has a store in a fridge but not in a freezer 7 use by 20 Nov date on it .
I had to get it off the internet  as none of the garden centres in a 2o mile radius stock it because  it does not have a long enough shelf life and needs a fridge to store it.  Plus at £ 6 or so a gallon for fuel it was the cheapest option.

 it is also said to be good for all sorts of other  creepies such as carrot root fly & onion fly , I have eight  rows of 17 station sown carrots & 100 overwintering onions ..last year the carrots were decimated with CRF

Cabbages are about £1.20 each in the supermarkets ,  that makes 6 cabbages or brassica harvestings and I'll have covered the costs

So this time I'll use the Nemasys it will cover 60 sq mtrs and as you use it 1/4 of the pack at a time I can get four hits a week apart on the raised beds till it is gone .

 
Next year I will use Nippon ant powder on half of the brassicas plantings as I have found a full 1 litre sized puffer bottle of it in the garage .   I will however still get the " Nemasys  Grow your Own "  nematode control for it can be used on all the beds and does not have any know side effects on humans or plants.

[Skirza]

 Good luck with the nematodes .....they did diddly squat to my cabbage root fly problems 

[Blonde]

Having returned from holiday to find things a wee bit overgrown ( hoW I hate seven weeks of holiday abroad  ) it took me a few days to get the raised beds back under control ..i then started to plant thing out .
 Now 3 weeks later I noticed that some of the transplanted cabbages were dropped over to one side and had a yellow tinged leaf or two low down .
 on pulling up the affected plants sure enough  the white maggot shaped 15 mm long lava of the cabbage root fly was ther e munching the stem of the cabbage some 8  mm below the soil line.


NOTE EDITED  from 15 mm to 8 mm  long  trust a guy to get his size wrong!

I know I can get a bio control called Nemasys Grow Your own ( £5 a punt for 60 sq mtrs control ) that will zapp the blighters and numerous other spiteful critters that attack brassicas and other root crops
Have any of you used it .. if so was it any good ?.


 Are there any " Grandads "   solutions out there to the prob that are still easily available  beside putting a fly collar around each plant at transplanting time.

Take a sheet of clear or black   plastic, put over the soil in your garden, seal the edges with bricks or dirt, leave to heat up on a hot day, the clear plastic will show condensation, but the black wont show it but it will occur.   Leave for a week then remove and plant into the soil.  called SOLARISATION   Kills all in the soil

[Plantoid]

Blond ,
I think that idea of solarization has been proved a fallacy for over ten years .. to"  kill everything " , the soil would have to be heated up to over 50 oC , what the dark plastic sheet does is  it starves the plants of light and most die  but not things like thistles , doc's or horsetail . ..
You can plant on the denuded soil but there will still be lots of weeds coming up that you will have to deal with .

 it does however help warm up the soil a bit earlier than open to the air  / weather soil and help the seeds / young plants get a kick start .

If you use clear plastic the plants still grow but with a slightly lighter colour and slightly weaker you also tend to get a bit of rot from the excessive humidity.
 
It can also make for far more slugs because the humidity and warmth are ideal breeding conditions .

Till very recently  I had  some 36  sq mtrs ( 6 x 6  ) of friable well manured soil in our back garden which was  covered in black 3 mm thick engineering construction /tanking  plastic sheets for two years . When they were removed in June this year  after the gear on them was sold the weeds came back in less than three weeks .

The slugs were also present in parts as well as two ant colonies  a  few mice burrows  with lots of chewed out acorns & hazel nuts .