I had a very similar query around this time last year Dave when I was new into sempomania. The rain was my biggest concern as it rained incessantly for months . Anyway I needn't have worried as they all came through with flying colours. The snow acts as insulation apparently ,although we had none here last winter . Free draining compost is essential and this includes removing the potting compost a lot of new semps are supplied in, as this can act like a mini sponge .
