I'm wondering how best to over-winter my dahlias in my London garden.
Last year I dug up the "posh" ones ('Bishop of Llandaff', 'Moonfire'
and seed-grown Dahlia coccinea var palmeri) but left some others in the
ground. In spring all the ones left in the ground came back, whereas I
had a few casualties amongst my stored tubers. I'm tempted to keep the
lot in the ground and cover them with mulch, but my concern is that
they might not survive if we have a wet winter (last year, although we
had a few very cold days, was pretty dry). Or am I behind the times
and do most people in the south of the UK leave their dahlias in the
ground over winter as a matter of course? If not, any tips on how to
prevent the stored ones from rotting?
Thanks.