On Friday, December 26, 2014 12:14:08 AM UTC-6, Julie Bove wrote:
>
> wrote in message:
>
> > I thought green skin was a sign that the potato had been 'sun burned.'
>
> How could that happen? They grow under the ground. It means they have been
> exposed to light after they were dug up.
>
>
BINGO!

They were left out and exposed to the sun for too long after being dug up. As soon as they are 'out of their nests' they should immediately be hauled away and out of the sun.