JennyC wrote:

I was wondering whether any URGlers have experience of keeping cacti in a
polytunnel?

Any info regarding ventilation, heating in winter etc would be good.

Which species? If you can keep them dry and above 5C worst case most
(apart from obvious tropical species and succulents from Madagascar)
will hang on but may be marked. I keep very temperature sensitive plants
indoors for the winter since I cannot ensure reliable electricity in
winter storms. It is worth separating them and keeping the most touchy
ones at the blind end possibly inside a second skin well away from drafts.

It is amazing how well a bubble wrap curtain will help keep the warm end
a lot warmer than the end where the door is. My experience is actually
with a long thin greenhouse, but I think it will translate well to a
polytunnel.

Regards,
Martin Brown