Out of interest I once put an adult weevil in a jar of pure bleach. It was still alive 24 hours later. Another one which would probably survive the Nuclear Holocaust, like the cockroaches.
Certainly agree about the peat based MPC used by Nurseries. They love that stuff. Non-peat with added grit is better, but still not perfect.
I was reading about a Fungal based soil additive which is supposed to be a very good control in an organic way. Very expensive and sadly only available in large quantities and once opened has a short shelf life.
Maybe it'll get cheaper if it becomes more widely known?
I suppose gardening clubs etc might bulk buy together?
The interesting claim is that the fungus is persistent, so once a plant has it on its roots, it will continue to attack the vine weevil grubs even when re-potted in fresh soil. If it becomes a regular addition to Nursery stock, then it could be good news for everyone.
I do know of one grower who is using it.
Thanks everyone. Great to hear all the different comments. I've binned my polyanthus but haven't drenched the compost in the pots yet as we had freezing temperatures and snow over the past few days! (Scottish Highlands ) Much milder now though so perhaps by the end of the week will use the provado, though the neighbours will probably think I've finally lost the plot .