David in Normandy wrote:
What is a potato day anyway?

It's an event held around the country at various places (typically the last
couple of weekends in January, iirc) where they get an awful lot of
different potatoes together for sale in one place (supplied by one or two
suppliers, presumably), plus a bunch of other peripheral activities.

I've only been to the Hampshire one so far (Nick has suggested we head for a
different one next year - Dulwich or the one near Coventry), which is why
the idea of organising one nearer home came up ... but their other interests
included a giant seed swap table (where my vova yellow tomato seeds came
from, which were one of my best tomatoes this year - and also my charbeneuse
noire tomato seeds, which are one of my worst tomatoes this year!), a few
heirloom seed suppliers, some new variety potato taste tests ... I think
someone was selling jam, too.