Organic caterpillar repellent?

[cottage garden]

My brassicas have been an absolute disaster this year. Eaten to shreds by slugs and snails and now covered in wiggly caterpillars. I HAD put collars on them and used nemotodes on the ground before planting. FAT lot of good that did.

Yesterday I went to visit an organic gardener and saw her long line of huge healthy, not remotely eaten, brassicas. Apparently she covers the area in masses of manure and then lots of organic blue slug pellets? then a layers of weed suppressant fabric which she cuts holes out for the plants. Finally she sprays them with a organic pesticide which the caterpillars hate the taste of....Any one any ideas..my local garden centre didn't have any.

I am definitely doing the above for my winter brassicas.

[HappyMouffe]

I put a netting frame (well, 'frame' is a bit of an exaggeration: bamboo canes topped with plastic bottles) over my brassicas - it has to be fine enough to stop the butterflies getting in. No butterflies = no caterpillars. It keeps the pigeons off too.

[momol]

Hi Cottage Garden, try some neem oil spray ( you have to dilute them with water and a bit of liquid dish detergent ). It works for a week to 10 days ( if it is not raining ), and after that you have to repeate the spraying ( and if it is rainy day, you would have to repeate spraying after rain ( it get wash away ).
It works by changing the eating habit of the larva (they became lethargic and has no appetite ) and they will eventually die due to starvations. The very young larva will be kill on spot but does not work very well at the late stage larva. It is also work for aphid.
I used them before until chaged to netting (I am too lazy to once in a while spraying them ) You could also use pyrentrum ( if I am spelling it correctly ),it is an extract of pyrentrum flower, which also works for aphid ( mind you, it will kill lady bugs too ! ), I used this one before using neem oil, it works very well but the organic version is very hard to get and it cost a fortune ( I bought mine at a japanese flower show some years ago, and somehow just can't recall the brand, sorry )
Hope it help,

Momol