If you are a southerner, you probably know that unripe, green tomatoes, when fried or made into chutney, can be a culinary delight. However, green potatoes? AVOID THEM!!

Neon Green Potato from Carolyn’s Garden, Not Photo Shopped! Beware, Even Green Tinged Potatoes Should not be Eaten.
Now is the time that many vegetable gardeners are harvesting the potatoes that they planted in late January-February. If, as recommended, you have been hilling up soil against the stem of the potato or kept adding soil and compost to a potato bin, the odds are good that you will not find any “green” potatoes. However, if the ever-growing bunches of potatoes have managed to heave themselves out of the ground and are exposed to sunlight or if the potatoes have been exposed to extremes of heat or cold — beware. Those greenish potatoes can be potentially deadly. In fact, even potatoes brought from the store, if not properly stored in a cool, dry, dark place, can develop a greenish tint if exposed to too much light.
The greenish hue that can be found on potatoes exposed to light is actually chlorophyll. Not a bad thing, you say, because we eat chlorophyll in many leafy greens. However in the potato, the presence of chlorophyll also indicates the presence of solanine, a glycoalkaloid poison found in species of nightshade. This bitter nerve toxin crystalline alkaloid is part of the plant’s defense against insects, disease, and predators. It is found primarily in the stems and leaves of potatoes but can also be found on any green spots on the skin of a potato and on buds.
Solanine interferes with the body’s ability to transmit impulses between cells. Ingested in large enough quantities, it can cause vomiting, diarrhea, headaches and even paralysis of the central nervous system. Though an average adult would have to eat a very large quantity of green tinged potatoes (which are often quite bitter, a good warning sign) to have neurological damage, children may be more susceptible to ill effects. In general, it is probably best to throw away any potatoes that have green eyes, sprouts, or greenish skins.
As B. Rosie Lerner, Extension Consumer Horticulturist at Purdue University says: “The next time you see a green potato, be thankful for that color change. It’s warning you of the presence of toxic solanine.”
Carolyn
Picture by Carolyn
More info about potatoes :
One Potato, Two Potato, Hopefully More