Brussels sprouts

Haven't grown them for forty years due to lack of room but this year put some in and covered them with a netting cage. Didn't stop the large whites from laying through the net but I eventually got rid of the caterpillars. Now that I have begun picking some, I find that they are covered in clouds of tiny grey flies. What should I have done to avoid this problem?

Thanks
stony

 

Souns like you have whiteflies there!
Big problem this time everywhere, they gone into my greenhouse as well. Pretty hard to avoid them, just gotta wash the sprouts very well before cooking.
You can use some pesticide as a prevention, any would do what you can buy in garden centres, will state on the packet wich one is good against flies.
An other thing is to cover them with very fine cloche to stop the flies, but i found this pretty hard to do, as they find their way through anything!

 

Maybe an insecticide at some point might have kept them down but when to spray? I don't fancy doing it after the sprouts are forming.
stony

 

Yeah, i know what you mean, i do not spray anything at all. Well it says on the packet how to spray, and when, normally can be eaten 14 days after spraying.
Otherwise we just have to put up with the flies, wash the veggies well before eating.
thats all i can say

 

Covering with enviromesh should work. I've used it for the last four or so years and it keeps out butterflies and aphids/greenfly too. The only problem I encountered this year was on two plants at the ends of the 'tunnels' where I hadn't secured the mesh properly - cabbage white got in, though I discovered its caterpillars and squished them before they did any significant damage.
Enviromesh isn't cheap though and I thought twice about investing in it, but it's been worth it as I use no chemicals and lose no crops.
Netting is fine for keeping off butterflies but you have to keep it clear of the leaves and it wont keep off the smaller pests.
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