"Devlin" wrote
Bob Hobden;878730 Wrote:
"Devlin" wrote-

what can I buy to prevent cabbage root fly larve-

Nothing available on the chemical shelf these days for the gardener.
Only
way is to use a collar around the stem so the fly can't get to the earth

around the stem to lay it's eggs. You can purchase these or make them
out of
anything that will last a season, roofing felt, carpet....... hole in
the
centre for the stem and slit so you can put it on/take it off.

I thought there was a solution you made up and dipped the young plants
in I think my grandfather used derris powder is that now a banned
product

He probably used BHC dust which is no longer available and neither is
Derris.

--
Regards
Bob Hobden
W.of London. UK