Red Thumb Fingerling Potatoes This page first published: Jun 16, 2005 · Modified: May 18, 2018 · by CooksInfo. Copyright © 2020 Red Thumb are fingerling potatoes, uniformly-shaped at 1 to 2 inches (2.5 to 5 cm) long, with smooth, bright red skin that is easily cleaned, and waxy, reddish-pinkish flesh. Early harvest. Cooking Tips Best roasted. Storage Hints Stores well.