Okinawan Purple Sweet Potatoes are a lovely and delicious cultivar, featuring a creamy, beige skin encasing gorgeous purple-magenta flesh. Full of the antioxidant anthocyanin, they’re also high polyphenols, vitamin C, and soluble fiber. These sweet potatoes are easy for the backyard gardener to grow in the U.S. climate.
Hello, Blue Zones fans from the new Netflix series, welcome — I’m watching, too! I’m an avid follower of all things Blue Zones, and I hope you’ll find the information here about Okinawan Sweet Potatoes helpful.
In the U.S., they’re harvested Sept/Oct, but will probably be difficult to find anywhere but specialty stores and farmers’ markets. If you want to grow them in your backyard garden next year, you should be able to find slips — the starter plant – next March or April at the big online retailers (see info below).
Also, if you’re interested in the soup mentioned during the Sardinia segment, I have a recipe on my food blog for Sardinian Longevity Minestrone, which was inspired by one of the Blue Zones books.
Beni imo sweet potatoes, also known as Okinawan or Hawaiian purple sweet potatoes, are a beautiful and nutritious cultivar with creamy white skin and vivid purple flesh These sweet potatoes were a dietary staple for the long-lived residents of Okinawa, Japan and are packed with antioxidants like anthocyanins. If you want to grow your own beni imo sweet potatoes, you’ll need to start with slips or vine cuttings rather than seeds. Here’s what you need to know to find beni imo sweet potato starts for your garden.
What are Beni Imo Sweet Potatoes?
Beni imo, meaning “red potato” in Japanese, is a striking purple-fleshed sweet potato variety that originated in Okinawa, Japan. These potatoes have a white or cream-colored skin with a bright purple interior that intensifies when cooked. The flesh is slightly drier and starchier than orange sweet potato varieties.
Beni imo sweet potatoes are known for their high concentration of antioxidant pigments called anthocyanins. The vibrant purple color comes from anthocyanins like cyanidin and peonidin These antioxidants have anti-inflammatory and anti-cancer benefits. Beni imo potatoes are also packed with vitamin C, provitamin A, and fiber.
This nutritious root vegetable was a staple crop for Okinawans, who are among the longest living people in the world. The traditional Okinawan diet, high in sweet potatoes as well as other vegetables, is believed to contribute to their longevity.
Beni Imo Sweet Potatoes Don’t Come from Seeds
Unlike most vegetables, sweet potatoes are not grown from tiny dried seeds. Instead, they are propagated from slips or cuttings taken from the vines of mature sweet potato plants. This is how sweet potato varieties like beni imo are grown commercially and in home gardens.
If you want to grow beni imo sweet potatoes in your garden, you’ll need to acquire starter plants known as slips or vine cuttings. The easiest way for home gardeners to get slips is to order them from a reputable online nursery that sells specialty vegetable starts. You can also try growing your own slips from a grocery store sweet potato.
Where to Buy Beni Imo Sweet Potato Slips Online
Searching for “beni imo sweet potato seeds” will leave you empty handed. Look instead for beni imo slips or vine cuttings from these top online sources:
Specialty Sweet Potato Growers
Some small farms and nurseries specialize in growing and selling slips of rare and heirloom sweet potato varieties like beni imo. These specialty growers often sell through their own websites or third party sites like Etsy. Be sure to order early, as uncommon varieties sell out quickly. Reputable beni imo slip sellers include:
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George’s Plant Farm – TN based farm with extensive sweet potato slip selection
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Rogue Valley Sweet Potatoes – Specialty grower in OR selling purple sweet potato slips
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Malo Farms – Hawaiian farm selling Okinawan purple sweet potato slips
Large Online Nurseries
Some large online plant nurseries carry purple sweet potato slips alongside more common varieties.Availability from the big retailers can sell out quickly, so order early.
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Burpee – Lists Purple Passion and other purple-fleshed varieties
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Gurney’s – Sells Purple Passion slips
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Jung Seed Company – Stocks limited quantities of purple varieties
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Johnnys Selected Seeds – Sells purple-fleshed Murasaki slips
Local Garden Nurseries
Your local independent garden center may carry sweet potato slips seasonally. Visit nurseries in your area in early spring to check availability. Call ahead to ask if they plan to stock purple sweet potato varieties.
Order Beni Imo Slips Early
Sweet potato slips are available for shipping in spring when the danger of frost has passed. Slips sold out quickly every year, so order yours early.
Look for beni imo and other purple sweet potato varieties to become available online in March and April. Place orders as soon as you see plants in stock. If you wait too long, the uncommon purple varieties will disappear from sellers’ inventories.
Once your slips arrive, they will be ready to plant out after any danger of frost is past, usually 4-6 weeks before your last expected spring frost date.
Growing Beni Imo Sweet Potato Slips Yourself
While buying slips online is the easiest route, you can also try propagating your own beni imo slips from a grocery store sweet potato.
To grow sweet potato slips:
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Obtain organically grown, non-sprouting sweet potatoes. Conventional potatoes are often treated to prevent sprouting. Choose small to medium sized tubers.
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Place tubers in water. Suspend the potato half submerged in a glass/jar of water with toothpicks.
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Change water daily. Refresh water to prevent rotting. New roots and leaves will sprout in 1-2 weeks.
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Cut slips when 4-6 inches tall. Gently twist off each shoot at the base, keeping root intact.
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Root cuttings in potting mix. Plant slips in small pots with potting soil. Grow on 4-6 weeks before transplanting outside. Discard the original tuber after taking cuttings.
The resulting slips may or may not produce purple potatoes like the parent. Growing from grocery store sweet potatoes is unpredictable compared to buying verified slips. But it can be an fun experiment!
What to Look for When Buying Beni Imo Slips
When buying or growing slips, look for:
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Healthy, green leaves – Avoid mold, shriveling, or insect damage
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Thick stems – Thin, wispy stems may not establish well
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Abundant white roots – Look for new fibrous root growth
High quality slips that are shipped and handled properly will transplant readily into your garden.
Plant Beni Imo Slips for Vibrant Purple Sweet Potatoes
While you won’t find beni imo sweet potato seeds for sale, viable slips are available from online vendors and local nurseries. Order early to secure your vibrant purple-fleshed tubers for harvest. With the right slips, you can enjoy growing your own nutritious beni imo sweet potatoes!
How Much Space is Needed to Grow Sweet Potatoes?
I won’t mince words here: you’ll want a big space!
Although the actual clusters of sweet potatoes do not take up too much two-dimensional area – in fact, you can absolutely grow them in a large burlap bag or container – they require nutrition from the leaves that the plant’s vines produce. And those vines grow incredibly long.
So, actual in-the-ground space needed by the potatoes: small’ish. Actual spread space needed for the vines: large.
I grow all of my sweet potatoes in a 10-foot x 10-foot plot. This plot is too small, lol, but it all works out: as the vines reach the fenced boundaries, I begin redirecting them to wrap around the plot’s edges in a circle.
Note that you can grow other plants in the same plot: anything that grows tall, whose own leaves will be well above the leaves of the sweet potato vines. Keep in mind, though, that late in the season, the area will be very densely covered in vines and leaves and will be difficult to reach. You could, however, plant something like bell peppers along the border of the plot, where you’ll easily be able to reach the peppers without squooshing the sweet potato vines by walking on them.
Last year, I grew honeynut squash in the sweet potato bed, and even though there were vines e.v.e.r.y.w.h.e.r.e, it all worked out rather well, and both harvests were quite abundant.
A Note for the 2024 Growing Season:
I’m having a heck of a time finding Okinawan potato slips this year. Sweet potato slips are usually available for pre-order now or purchase in March or April. For years, I’ve bought from Baker Creek Seeds, but they don’t seem to carry them this year. In fact, their sweet potato inventory is shockingly small. I’ve found listings on Etsy and Amazon, but you’ll need to understand the risk of buying from random growers who might be inexperienced at growing, nourishing, and shipping slips. I’ve found a few retail sources for the purple potatoes mentioned in the Netflix special (purple skin and purple flesh), including Johnny’s Seeds and a new variety at Baker Creek. Also consider growing Murasaki potatoes, which are a magenta-skinned, white-fleshed Japanese potato that are quite delicious.Update: A kind reader wrote to let me know that they found Okinawan Potato slips for sale at George’s Plant Farm. I don’t have personal experience with this grower, but they have an amazing inventory of sweet potatoes. Worth a look!Update mid-April 2024: It looks like George’s Plant Farm has sold out of the Okinawan Potato slips! It’s late in the buying season now, but still not too late: I would go for the Purple Passion or the Red Japanese. The folks there have no idea who I am, and I’m not getting a commission; I’m just so excited to see a grower offer such a beautiful variety of sweet potatoes. A farm after my own heart!
I used to purchase my slips from Baker Creek Seeds. I’d hit their Live Plants page early in March, and sign up for the back-in-stock notification. As soon as I get word that they’re ready to purchase, I pounce, no matter the date or weather forecast. In 2024, however, I didn’t have any luck getting varieties I was interested in.
Once the slips arrive, I keep them in their little plastic shipping bags, rolled down to expose the upper leaves for aeration, sitting firmly in a ramekin in a morning-sunny window until I’m ready to plant. Keep the soil plugs lightly watered, and the slips will thrive. This year’s slips:
Growing Sweet Potatoes From Seed!
FAQ
What is the difference between Beni-imo and sweet potatoes?
These are the sweet potatoes famously baked and sold from trucks on the streets of Japan as Yaki-Imo. Their flesh is incredibly sweet and more starchy than other sweet potatoes. It is a member of the sweet potato family. Beni Imo, on the other hand, have a lighter skin and bright purple interior.
Is Beni Imo healthy?
Anthocyanin is an antioxidant and Beni Imo contains 150% more antioxidant than blueberry, which makes them a powerful cancer fighting superfood.
What is the most delicious sweet potato variety?
Which sweet potato is the sweetest? Sweetest is subjective but relatively speaking, Garnets and Hannahs are mildly sweet. Purple and Jewels are moderately sweet and the Japanese variety tend to be the sweetest.
What month is best to plant sweet potatoes?
When are sweet potatoes planted? Before planting sweet potatoes, you should also consider the right time to plant them. This will vary according to the area you are in, as they thrive in warm climates. It is best to plant them between April and June.