Thome Black Potatoes This page first published: Apr 7, 2005 · Updated: Jun 1, 2018 · by CooksInfo. Copyright © 2021 · This post may contain affiliate links · This blog generates income via ads · Thome Black Potatoes are oblong, with dark purple skin and yellow flesh. They are grown in home gardens. History Notes Thome Black Potatoes are from County Donegal, Ireland.