Prevent Potatoes from Sprouting | Yankee Kitchen
You can minimize the occurrence of sprouts and green patches if you store potatoes in a cool, dark, dry area in a mesh (not plastic) bag or basket for good airflow. The eyes are undeveloped buds. (In late spring, they can be cut out and planted for an early fall crop.) They are edible, but if sprouts develop from them, cut them out. The sprouts are usually bitter and often blacken when cooked; also, they contain solanine, a naturally occurring alkaloid that is toxic.
The green patches that form on most potatoes over time are chlorophyll, which develops when the potato is exposed to too much light (either sun or artificial sources) after harvest. Chlorophyll is harmless in itself, but it indicates a simultaneous increase in the potato’s level of solanine. Cut away the green parts before cooking.