Question:
I had a great potato harvest this year. However, I noticed that some of the potato skins had areas with a green tint. I've been told they're poisonous. Should I throw away the green potatoes?Answer:
- Potatoes are edible tubers that grow underground. It is important to keep the tubers covered during the growing season so that maturing potatoes are not exposed to sunlight.
- The potato skin turns green or bluish-green when exposed to light. The damaged area can be large or small, depending on the exposure. The green part of the skin contains toxins and should not be eaten, but this is not the main issue.
- The green coloration simply indicates that the potato has been exposed to light, which prompts it to produce more chlorophyll, and chlorophyll is not toxic to humans.
- The real problem is that light exposure also causes the formation of a substance called solanine, a glycoalkaloid that can be toxic in large amounts. Solanine is a natural defense mechanism of the potato to fight off fungus and pests. It can also be produced when a potato is bruised. Since solanine accumulates only under the skin and not throughout the potato, it is safe to peel away the skin and a thin layer of white flesh before cooking; however, any completely green potato should be discarded.
- This is a personal issue that does not affect the other potatoes you harvested, so enjoy them.
- Potatoes should be stored in a cool, dark place. Use a brown paper bag or a cardboard box covered with newspaper.
- Dark or amber plastic bags can also be used, but you need to punch holes for air circulation to prevent moisture buildup. This helps keep the potatoes dry and mold-free. The kitchen counter is not ideal for storage, except for short-term use.
- Next year, when you plant potatoes, avoid this problem by covering the seed potatoes with potting soil or other organic matter as they grow. This technique, known as 'Hilling,' often involves adding a foot or more of material during the growing cycle.