Topic: Brassicas: Annual Humiliation

[Number Six]

Once again, many thanks for the excellent replies, most of which I am considering for next year's 'strategy'. 

Unfortunately, while I am impressed by AmazingRotavator's large tunnel, my plot is on agricultural land (not designated as an allotment) and such a structure would not be permitted without planning permission. For eg, I had to remove a greenhouse and shed a few years ago.

[ancellsfarmer]

Update on Soda Bic/salt treatment.
Delayed in application to 07.30 today due to persistant light showers . General spraying with trigger spray to all visible caterpillars and underleaf surfaces. Noted that treated caterpillars became motionless in a minute or so. Returned this afternoon to find almost no active caterpillars, some "dead"  and witnessed several being dismembered into manageable sections and whisked away by wasps. Bet they wouldnt have wanted them if Bug-gunned!

[ed dibbles]

I found much the same, ancellsfarmer. Those caterpillars really don't like it one bit.

[Number Six]

And I finally tried the soda/detergent/salt mix last night and was amazed at the reaction of the caterpillars. Only wish I had used it before the little blighters had eaten half the leaves! Many thanks to Ed for the recipe

[squeezyjohn]

I will add myself to the herds of people suggesting the builder's debris netting on some kind of hoop support.

This year I did it for the first time and not only have the pigeons and cabbage whites kept right away from the plants - I concur that the shelter from the wind really gets brassicas growing quickly and well.  I've had the biggest and most succulent pest-free calabrese and kohl rabi this year ... the brussels sprouts, purple sprouting and kale are looking so healthy - only cabbages were a bit of a failure - and that was due to slug damage.

Rigging up a support from some water pipe with bamboo to stick it in the ground at each end of the hoops is really easy and not too expensive given how it improves the crop.  I weighed my netting down with bricks and bits of wood.

[George the Pigman]

We use a lot of scaffolders netting on our site as we have terrible problems with wood pigeons. It keeps them off and is supposed to keep butterflies from getting in to lay eggs but I am not completely convinced! My Kale plants have recently been chomped by caterpillars even though they are under it.
What it does do is bring on brassicas a treat! I thinks it creates a microclimate with slightly higher humidity and temperature that brings them on faster.
Of course you shouldn't use it for plants that may need pollination by insects! eg fruit, legumes, curcubits etc

[lottie lou]

What it does do is bring on brassicas a treat! I thinks it creates a microclimate with slightly higher humidity and temperature that brings them on faster.

Yes, and you should see the size of my weeds.

[ancellsfarmer]

Update on Soda Bic/salt treatment.
Delayed in application to 07.30 today due to persistant light showers . General spraying with trigger spray to all visible caterpillars and underleaf surfaces. Noted that treated caterpillars became motionless in a minute or so. Returned this afternoon to find almost no active caterpillars, some "dead"  and witnessed several being dismembered into manageable sections and whisked away by wasps. Bet they wouldnt have wanted them if Bug-gunned!

Update 7 days after treatment:
Revisited plot for the first time today since Monday. I still have a few large caterpillars, some medium caterpillars and several "coach-park "arrays of little tiny hatchlings.
The large I suspect , were hiding last week and survived. The medium (of which there are several) could have migrated from the swedes which are now bare ribbed, and the tiny, just hatched. All (?) resprayed with same miture at 09.00 Reinspected at 1pm with hardly any showing signs of movement. Wasps very active on foraging caterpillar corpes..Aim to revisit on Tuesday and hope for a clear crop. Many thanks to Ed for recipe.

[strawberry1]

good mesh does the trick but the plants need to be protected from seed sowing time, no pesticides needed and plants need to be away from the sides of the butterfly mesh but ok touching with enviromesh

[ancellsfarmer]

Update on Soda Bic/salt treatment.
Delayed in application to 07.30 today due to persistant light showers . General spraying with trigger spray to all visible caterpillars and underleaf surfaces. Noted that treated caterpillars became motionless in a minute or so. Returned this afternoon to find almost no active caterpillars, some "dead"  and witnessed several being dismembered into manageable sections and whisked away by wasps. Bet they wouldnt have wanted them if Bug-gunned!

Update 7 days after treatment:
Revisited plot for the first time today since Monday. I still have a few large caterpillars, some medium caterpillars and several "coach-park "arrays of little tiny hatchlings.
The large I suspect , were hiding last week and survived. The medium (of which there are several) could have migrated from the swedes which are now bare ribbed, and the tiny, just hatched. All (?) resprayed with same miture at 09.00 Reinspected at 1pm with hardly any showing signs of movement. Wasps very active on foraging caterpillar corpes..Aim to revisit on Tuesday and hope for a clear crop. Many thanks to Ed for recipe.

Tuesday bulletin.
Very many less caterpillars but did find one lowdown leaf with no less than 31 critters! so this spoilt the triumphalism. Seems to be single odd large survivors(possibly those quick enough to drop at the first contact) and newly hatched batches. How long is their incubation period. Still loads of butterflies at the moment so the caterpillar wars will continue. Maybe we need another ingredient... suggestions with test results please

[Number Six]

No sign of "coach parks" since starting the spraying, but am still finding a few large caterpillars such as this one today:

[rokerman1973]

Try something like this. Note props in the large one to stop the snow collapsing it.

What sort of height are these - they look great. What height would you go for Brussels sprouts for example. What length of polypipe are you using and how do you attach the polypipe to the wooden frame and the netting to the whole structure. Desperate to copy your design if that's okay ready for next year. Many thanks Al

[Big Gee]

Now reached that time of year when I watch my brassica crop (savoy cabbage, calabrese, colly and spouts) being chomped by caterpillars etc. Had some cheap Wilko netting over them which stopped the pigeons getting at them but not the butterflies - and then the sprouts outgrew the netting so I removed it and replaced it with 'dangling CDs'.

The colly and calabrese have already produced a good crop but I obviously need to do a re-think for next year to protect the cabbage & sprouts. Greatly appreciate any advice on netting or any other techniques for protecting brassicas.

Many thanks

John

The only truly effective way to prevent cabbage root fly, white butterflies (or carrot root fly for that matter) in my experience is to use a barrier John.

By far the cheapest (often freebies) is to get your hands on som scaffolding debris net. Scaffolders are supposed to renew it after every job. The other alternative is Veggiemesh (cheaper than Enviromesh). All of these work exceptinally well - a pity they don't deter slugs so well - but they do help with them as well!

Debris net is a brilliant find - it's the perfect width and is very easy to use (unike netting, which often does my head in!) The other component is some alkathene piping a few canes for a ridge and some clips and tent pegs from your local £ shop to keep the edge of the netting down!

Here's an example on my plot:



I hope that helps in some small way!

G.

[Amazingrotavator(Derby)]

Try something like this. Note props in the large one to stop the snow collapsing it.

What sort of height are these - they look great. What height would you go for Brussels sprouts for example. What length of polypipe are you using and how do you attach the polypipe to the wooden frame and the netting to the whole structure. Desperate to copy your design if that's okay ready for next year. Many thanks Al

The timber is 2"x 1" (Tilers lathes), The pipe is 25mm. The structure is 8' long x 3' wide and 2' high. The pipe is approx. 70" long. I estimated the length of pipe just for cabbages. I built the bigger one for Brussels. I screwed through the pipe into the frame and stapled the net to the frame. Mine are as good as the day I built them (3 years) even though our cats climb on them. Good luck Al.

[George the Pigman]

Are the holes in the scaffolding netting small enough to stop the carrot root fly getting in? They usually recommend fleece which has much finer holes.

[Big Gee]

Are the holes in the scaffolding netting small enough to stop the carrot root fly getting in? They usually recommend fleece which has much finer holes.

I believe so. It is quite fine, although fleece is much finer of course.

I haven't had any carrot fly attacks through debis net, but if anyone has I would be interested to hear about it.

G.

[Number Six]

Many thanks to Big Gee et al for the excellent advice. As mentioned earlier, I'm fighting shy of building any 'permanent' structures as my plot is on agricultural land and I've had a run-in with the local planning enforcement chap before. However, Ed's spray is doing a grand job in significantly reducing the chomping of my brussel sprouts

[Big Gee]

Many thanks to Big Gee et al for the excellent advice. As mentioned earlier, I'm fighting shy of building any 'permanent' structures as my plot is on agricultural land and I've had a run-in with the local planning enforcement chap before. However, Ed's spray is doing a grand job in significantly reducing the chomping of my brussel sprouts

You're welcome Number Six. One suggestion for you is to use net 'tunnels' but of the temporary type - without building any permanent structures around raised beds.

The structures I use can be erected in 20 minutes and taken down again & stored in about 10 minutes.