> >Is it preferable to let them "harden",,, i.e. leave the larger ones in
> the ground for a while so they store longer into winter?
>
>
Yes, leave them in the ground as long as is practical. That's where they
are at home. Some varieties of potatoes that I grow (for example, Yukon
Gold) will often mature and die completely by the end of June. But I leave
them
in the ground until October or November else they will shrivel and
deteriorate in the summer heat.