Blue Potatoes: Plant an Easy-to-Grow Heirloom in the Spring
These ancient blue potatoes are nutty,robustly flavored and full of antioxidents.Photos by Doreen G. Howard
With thoughts of crisp blue potato skins heaped with bacon bits and melted cheese, I planted my first All Blue potato in 1990. I’ve been hooked ever since. I even eat blue mashed potatoes.
As a kid I hated potatoes. My Mom cooked only mashed potatoes, the consistency of wallpaper paste, with no gravy. Adulthood wasn’t much better; I even avoided French fries. Children changed the equation; I needed to set a positive example. A seed catalog arrived one spring with photos of vivid blue-skinned potatoes. The flesh was blue, too. I thought my son would eat them out of curiosity. I was really projecting my own potato problems, because he already was a French fry and baked potato fan.
All Blue potatoes are probably the most direct descendent of potatoes found almost 10,000 years ago high in the Peruvian Andes mountains. Blue and purple pigments developed as mechanisms to shield tubers from excessive levels of ultra violet light found at high altitudes.
Tubers exposed to direct sunlight turns green, which indicates large amounts of solanine, a compound that sickens humans. All potatoes contain tiny amounts of solanine, but green portions contain toxic amounts. The first potatoes grew in crevices and rocky outcroppings where the soil is very shallow. Developing tubers had only a scant layer of dirt to cover them, so purple and blue pigments evolved over time as a natural sunshade.
Any potato is easy to grow, and All Blues are even easier, as they seem to resist fungal diseases. I place tubers on top of a garden bed that has been enriched with compost and a bit of soil sulfur. Potatoes develop scab in alkaline soils (6.0 to 6.5 pH is ideal), and my ground is 7.2 pH. So I add sulfur to acidify the soil. I use whole tubers, instead of cutting them into chunks, as many gardeners do. I feel I’m avoiding a rot problem, as early spring in my area is cold and wet.
All Blue is just one of the heirloom potatoes I grow. Red Cranberry and Russian Banana Fingerling are both as colorful and tasty.
After spacing the potatoes about 12 inches apart in every direction, I cover the bed with about a foot of straw. That’s all I do. Other easy techniques are to grow potatoes in a wire cage above the ground or in grow bags.
You can start harvesting baby or “new” potatoes when plants flower. And, yes, their flowers are blue, too!
Blue Potato Tips
- Plants survive temperatures down to 15ºF with little or no protection. Place a double layer of newspaper over plants when freezes threaten and foliage is still actively growing.
- Microwave to retain the blue color, or steam potatoes just to the point of tenderness. Baking, boiling and stewing will fade colors slightly.
- Blue fleshed potatoes have more vitamins and antioxidants than white potatoes. They have as much anti-oxidant power as Brussels sprouts, kale and spinach.
What do you think about the All Blue Potato? Please share your comments—and any questions—by posting below!
About This Blog
Get inspired by Robin Sweetser's backyard gardening tips. Robin has been a contributor to The Old Farmer's Almanac and the All-Seasons Garden Guide for many years. She and her partner Tom have a small greenhouse business and also sell plants, cut flowers, and vegetables at their local Farmer's Market.