The Color Purple
As a general rule of thumb, more deeply colored vegetables and fruit have high antioxidant levels. In the case of potatoes, it is the anthocyanins that provide the deep purple color. The color typically fades toward blue when the potatoes are cooked. Research shows these potatoes have anti-inflammatory properties and are high in fiber. They are also rich in vitamin C.
Purple Potato Varieties
Like all potatoes, purple potatoes may be large bakers, small round tubers or fingerlings. Here are possible varieties:
- Peruvian Purple – fingerling; purple throughout.
- Purple Viking – snow-white flesh and true purple skin with pink or red splashes.
- Purple Majesty – very deep purple.
- Purple Pelisse – another fingerling; deep violet in color.
- Adirondack Blue – More blue than purple, with purplish flesh.
- Midnight Moon – purple skin and golden yellow flesh.
Growing Purple Potatoes
All potatoes need rich, fertile soil and good drainage. Cool-season plants, they do best when planted in early spring so they can make growth before hot temperatures hit. Grow them in full sun in all USDA Zones. Keep potatoes well-watered during growth but stop watering once they flower to promote tuber development. Cover them with several inches of soil – this is known as “hilling” – at least twice while growing to protect tubers from light.
Most gardeners pre-sprout, or chit, their potatoes. This allows you to get an early start on the growing season. Plant three to six inches deep; fingerlings are planted more shallowly due to their smaller size. Plant in individual holes or a trench and hill the potatoes at least twice while growing by covering with several inches of soil. Keep weeds down with mulch or hoeing.
Harvesting Purple Potatoes
You can harvest new potatoes about three weeks after flowering – dig carefully to avoid bruising tubers or damaging roots. New potatoes don’t store well and should be eaten within a day or two. Mature potatoes are usually ready three or four weeks after the tops die down. In either case, do not wash after harvest – it encourages rot. Brush off loose soil.
Storing Purple Potatoes
Different varieties of purple potatoes will have different storage times. Always cure your potatoes prior to storing. Place them in a single layer in a warm, well-ventilated shady place for a week or two. Check for bruises and small areas of decay before storage – these potatoes can still be used immediately by cutting out the bad spots. Store in a dark, cold but not freezing area with high humidity.