A Potato That Actually Helps Optimize Blood Sugar? Yep! It’s a Beautiful Shade of Blue

Blue potatoes just may be the perfect food: The tubers are a great source of healthy nutrients. Not only are they safe to eat, but consuming the spuds are study-proven to protect you against diseases like diabetes. And they’re simple enough to grow in a container garden right in your backyard with a few easy steps.

Blue potatoes are packed with nutrients

Blue potatoes, which are also called purple potatoes, grow blue naturally and they pack a nutritional punch. Like all potatoes, this variety boasts more potassium than a banana, plus fiber, vitamin B6 and vitamin C. But what sets blue potatoes apart is their high anthocyanin content. A study published in the journal Food Science and Technology found there can be up to 57 mg of anthocyanins per 100 g of blue potatoes. The healthful compound, also found in berries and other blue, red and purple produce, is linked to a number of health benefits, from lower blood pressure to better memory.

Blue potatoes reduce the risk of diabetes

Finnish researchers reporting in the journal American Chemical Society say that regularly eating blue potatoes can lower your risk of diabetes and help control blood sugar. They conducted a lab study, where they determined that blue potatoes and other red, purple and blue produce like radishes and purple carrots contain acylated anthocyanins, a variety of the plant pigment that is poorly absorbed during digestion. These compounds help to slow the breakdown of carbohydrates into glucose. That means the body processes less sugar, so you’re less likely to experience sharp spikes and drops in your blood sugar that drain your energy and, over time, can lead to diabetes.  

The researchers note that the healthful nutrients also act as probiotics during digestion, plus help to fortify the intestinal barrier, which is essential for absorbing nutrients. What’s more, blue potatoes, which retain their deep blue hue when they’re cooked, have a glycemic index of 77 (the glycemic index of white potatoes is 93). That means you’ll see a smaller spike and drop in glucose and your energy levels will stay more steady after eating blue potatoes than they would after having a white potato.

What’s the best way to cook blue potatoes?

If you’re looking to lock in nutrients, you’ll want to air-fry the spuds. Researchers in Food Chemistry found that this cooking method increased the available antioxidants in the tubers by 31%. But if crispy air-fried potatoes aren’t for you, try this delicious recipe for roasted blue potatoes from First for Women Food Editor Charles Grayauskie: “I like to cut blue potatoes into 1″-2″ pieces and roast them with the skin on at 400°F with a little olive oil, rosemary and garlic. You can also mix them up with red-skin and Yukon golds and roast them all together for a colorful side dish.”

Growing your own blue potatoes is surprisingly easy

While blue potatoes used to be considered rare, these days you can find them at many farmers markets and grocery stores like Publix, Kroger and HEB. But you can also grow your own! “More and more people have started growing blue potatoes not only for their nutritional benefits, but also because potatoes are one of the easiest crops to grow,” says professional kitchen garden designer Resh Gala, author of the forthcoming book Vegetable Gardening Made Easy available this fall.

Gala recommends planting seed potatoes, which are blue potatoes that have started growing little white buds on them. They are available to purchase at online seed shops or garden supply stores (Tractor Supply, $3.99), or you can sprout your own by placing organic blue potatoes purchased from the supermarket in a dark corner of your pantry or a cabinet for several weeks until they form buds.

Here, how to grow your own:

Step 1 : Pick the right container and soil

When you’re ready to plant, Gala suggests picking up a large whiskey barrel planter (available at Lowes, $54.98) with drainage holes drilled into the bottom, or a 10-gallon grow bag (available at Amazon, $13.99). Either container will be able to hold 3 seed potatoes.

Next, mix together equal parts good-quality organic potting soil, peat moss and compost, then fill up your container or grow bag with 6 to 8 inches of the soil blend. Nestle three potatoes (sprouting side up) into the soil, then cover them with another 6 to 8 inches of the soil blend. Water well.

Step 2: Give blue potatoes plenty of sun

“Potatoes need 8 to 10 hours of sunlight a day to grow well,” notes Gala. “Regular watering is important too, to make sure that the soil doesn’t dry out.”

But most importantly, Gala suggests “hilling” your potatoes — or filling the pot with layers of a compost and potting soil mixture. “Once the leafy green tops of your potato plants are 6 to 8 inches tall, add a few inches of compost and/or good quality organic soil on top of your plants. Allow some of the leafy growth to get buried under the soil, but make sure two-thirds of the plant is still above the soil.

For best results, you’ll repeat this hilling process two to three times throughout the growing season, until the soil reaches the very top of the container and you can’t add any more. At this point, add some straw as your last layer on top and let the leaves continue to grow.

Step 3: Harvest your potato bounty!

Blue potatoes are ready to harvest in 90 to 100 days, and you’ll know they are ready when their foliage starts yellowing and browning and the plant looks like it’s almost dead, says Gala. At that point, you need to stop watering your plant for at least a week to 10 days. Tip: Check the weather to make sure it doesn’t rain before you harvest, as wet potatoes don’t store well.

To harvest your potatoes, simply turn the container upside down onto a tarp to empty it out and sift through the soil to find your blue potatoes. “Get the little ones in your life involved too, as it can be a fun treasure hunt activity to search for potatoes in the soil,” she says.

Alternatively, you can harvest earlier if you wish to enjoy baby blue potatoes, or new potatoes. “Just wait for the plants to start flowering first, as that’s a sign that it’s forming potatoes under the soil,” she notes.

Once you’ve harvested your potatoes, don’t forget to “cure” them for 2 to 3 weeks to get them ready for storage. All that means is that you shouldn’t wash the potatoes after harvesting — simply brush off excess dirt and store in a dark place. This process helps thicken the skin so the potatoes can store well for a longer period of time, notes Gala. “And don’t forget to make some delicious mashed blue potatoes or roast them in the oven and impress your friends and family!”