Farm1 wrote:
Steve I live in Australia but in a very frosty place (down to -10 C
some years but always at least one or more -5C). My agapanthus stay
in the ground all the time. The leaves turn to mush over winter but
they don't have any trouble surviving even the -10C. But then my soil
doesn't get soggy in winter. I find agapanthus are one of the
toughest plants in my garden.

The dwarf varieties, like the tinkerbell, are not entirely hardy and in
pots they are vulnerable. These are late flowering as well, around
Sept. I suppose Steve thinks that frost will get to them. I'd still
keep them outside, in their pots, but mulch them and put them somewhere
sheltered for winter protection if worried.

I've got some amongst our alliums collection. Some white ones which I
forgot the name. They've been there years and beside mulching before
winter there's nothing else I do.