Out of the Blue: Growing Blue and Purple Potatoes

Health Benefits of Purple Potatoes

Purple potatoes boast more health benefits than their white counterparts. The golden rule with any fruit or vegetable is the darker and deeper the color, the more nutritional benefits it packs. They contain carotenoids and the color comes from their flavonoid content.

These potatoes are high in carbohydrates, low in fat, high in potassium, and contain a small amount of iron and a moderate amount of dietary fiber, which can help regulate blood sugar and prevent high cholesterol. They’ve also shown anti-inflammatory properties.

Blue potatoes also contain anthocyanins—an immunity-building anti-oxidant that fights free radicals, reducing the risk of cardiovascular disease, stroke and cancer. The skin is rich in vitamin C and contains polyphenols. The skin also helps seal in the nutrients while cooking, so try to leave it intact.

Using Purple Potatoes

Purple potatoes are native to South America and they boast a purple-pigmented skin and flesh that, for most varieties, changes to a bluish color once cooked. The strange and unusual appearance of purple potatoes makes them a great addition to any meal and a brilliant talking point. Serve them up in your favorite potato salad, as a side dish with chicken, or mash, roast or fry them. Get creative!

Potato Growing Conditions

Potatoes love a pH between 5 and 6. Late spring is the best time to plant potatoes. You’ll need about 3 gal. of soil per pot and potatoes love a 50:50 mix of compost and potting soil. They need 60-90 days of frost-free growing, making them great to start in bags in a greenhouse. Potatoes don’t need that much attention once established. Make sure you weed young plants regularly to avoid having them fight with other plants for nutrients, keep them well-watered, and feed them regularly. Most growers agree a granular nutrient works best.

Weeds shouldn’t be a problem as they mature because they form a canopy of leaves that should keep them at bay, but keep in mind that heavy soil can encourage potato scab. If you buy seed potatoes, ensure they are certified as disease-free to protect your soil and your crop.

Tubers should be planted about a foot apart, about 5-in. deep, and then covered with about a foot of mulch. As they start to grow, add more soil over top to keep them covered, without covering the top 6-in. of leaves. This is important—if the growing potatoes are exposed top too much light, they’ll start to turn green.

If you find some out-of-this-world potatoes you would like to cultivate, allow the potato to sprout slightly, then cut it into chunks so there are one or two “eyes” per chunk. Lay the pieces out for one or two days to dry—they should callous over slightly—then plant with the eye facing up.

When it’s time to harvest, make sure you remove all of the tubers from the ground; this year’s tubers are a sure way to invite disease into next year’s crop. Also avoid planting potatoes in the same place year after year.

Potato Pests

When conditions are dry, you will probably find potato moths lurking. They lay eggs at night on the foliage and tubers. To avoid infestation on the tubers, make sure they are always covered.

Harvesting Potatoes

You can begin harvesting your potatoes when they start to flower. Harvest by hand and as often as you like. You can scout smaller ones from underneath without disturbing the rest.

Once harvested, dry them quickly in a dark place. If exposed to excessive light, they will start to turn green and green potatoes are poisonous. The best thing about potatoes is you can pretty much harvest all year in a good climate. Enjoy!