Malcolm Stewart wrote:

"Peter James" wrote in message
.. .
kaz44 wrote:

Pack the holes with
saltpetre and plug the top of the holes with putty and leave it all
winter.

As private individuals, how can we get hold of the saltpetre (potassium
nitrate?) ?
I don't know. I do know that my farmer friend was able to get it. Try
your local Agricultural Supplier and Fertiliser Merchant. Or maybe a
wholesale chemist might be able to help. I know that saltpetre is used
in the manufacture of explosives so it might be a problem. Have you
googled for it?

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