Growing purple sweet potatoes is super easy and anyone can do it. You can even grow them in containers! Purple sweet potatoes are healthy and filling and they store very well. In this post, we’ll go over everything that you need to know in order to grow purple sweet potatoes.
Purple sweet potatoes are a bit different than the common orange sweet potatoes that we know so well.
They have a different texture (heavier and creamier) and they are not as sweet as the orange potatoes. They are super healthy for us (more details on that later) and they are just as easy to grow as orange sweet potatoes.
I got my first purple sweet potatoes at a farmer’s market years ago. I was walking around and noticed a vegetable that I hadn’t seen before. I got curious and bought a few of them.
I didn’t mean to grow them, I simply wanted to taste them. I tried to sprout a regular orange potato that year to produce slips that I could plant in the garden but it didn’t work… My potato grew many roots but not one slip.
Growing vibrant purple sweet potatoes is possible across a wide range of planting zones with the right care and variety selection. These antioxidant-rich tubers come in stunning hues from deep purple to vivid magenta, and offer unique nutritional benefits beyond their orange cousins.
While thriving in hot humid climates, gardeners from warm Southern zones to cooler Northern regions can cultivate bountiful crops of purple sweet potatoes. With a few simple strategies to boost warmth and extend the growing season purple sweet potato success can be achieved even in chilly zones.
Best Planting Zones for Purple Sweet Potatoes
Purple sweet potatoes prefer tropical conditions but can be grown in the following zones
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Zones 8-11 – The hot humid climates in these zones are ideal for growing purple sweet potatoes. Plant slips after all danger of frost when soil temperatures reach at least 65°F.
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Zones 6-7 – With care, purple sweet potatoes can flourish in these moderate zones. Use season extending techniques like black plastic mulch and wait until late spring to plant.
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Zones 5 and cooler – Growing purple sweet potatoes is challenging but possible in cooler zones. Start plants indoors, use row covers, and select early maturing varieties.
Growing Purple Sweet Potatoes in Cooler Climate Zones
Don’t let a short growing season stop you from raising purple sweet potatoes. Employ these tips for success in cooler zones:
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Start slips indoors up to 8 weeks before your last expected frost date. Gradually harden off plants before transplanting.
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Use black plastic mulch over planting rows to warm the soil, accelerate growth, and prevent weeds.
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Cover young plants with fabric row covers at night if temperatures may dip below 50°F.
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Hill soil over the crowns throughout the season to insulate developing tubers from cool temps.
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Provide wind protection if chilling breezes could stress young plants.
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Pick early maturing varieties suited to your zone’s season length.
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Irrigate regularly as plants prefer consistent moisture in cooler conditions.
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Harvest potatoes 1-2 weeks before first frost then cure properly for storage.
Growing Purple Sweet Potatoes in Hot Zones
Gardeners in zones 8-11 can easily achieve impressive yields of purple sweet potatoes. Follow these reliable tips:
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Plant slips 1-2 weeks after final spring frost when soil temperatures exceed 65°F.
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Space slips 12-15 inches apart in rows spaced 3-4 feet apart to allow room for plants to spread.
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Loose, sandy loam soil enriched with compost encourages the best potato development.
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Water plants regularly until established, then mature plants tolerate some drought.
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Apply a balanced liquid fertilizer every 2-4 weeks throughout the growing season.
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Remove any flowers to direct more energy towards the tubers.
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Carefully dig potatoes around 90-120 days after planting before heavy frosts arrive.
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Cure harvested potatoes for 1-2 weeks before long term storage.
Ideal Growing Conditions for Purple Sweet Potatoes
To maximize growth and yields, purple sweet potatoes require:
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Soil Temperature – Minimum of 65°F for active growth and tuber production.
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Soil pH – Slightly acidic conditions, between 5.6 and 6.2 pH.
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Sun – At least 8 hours of direct sun per day.
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Soil – Loose, sandy loam enriched with compost for drainage and nutrients.
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Water – Consistent moisture, around 1″ per week. Avoid overly wet soils.
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Humidity – Thrives in 60% humidity or higher.
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Air Temperature – 75-85°F during the day, above 60°F at night.
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Fertilizer – Moderate feeding with a balanced fertilizer every 2-4 weeks.
Troubleshooting Purple Sweet Potato Growing Issues
A few potential problems may arise when cultivating purple sweet potatoes:
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Cool weather leads to stunted growth and reduced yields.
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Overly wet soil causes tubers to rot – improve drainage.
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Drought stress inhibits leaf and root development.
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Heavy clay soil impedes proper tuber formation.
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Nutrient deficiencies manifesting as small vines.
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Wireworms, grubs, or sweet potato weevils feeding on plants.
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Diseases like stem rot, scurf, pox or leaf spot.
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Frost or freeze damage to young, tender plants.
Careful crop care and prompt issue resolution will prevent most problems with purple sweet potatoes.
With the right cultivar selection and a few simple season extending techniques, growing the antioxidant-rich purple sweet potato can be successful across a wide span of planting zones. Even gardeners in cooler Northern regions can enjoy harvesting plump, vibrant purple tubers. Test your green thumb with this satisfying, nutrition-packed crop!
What is an Okinawan Sweet Potato? What does it taste like?
Despite the geographic name famous for cultivating them, they’re also commonly grown in Hawaii and are often known as the Hawaiian Sweet Potato.
Okinawan Sweet Potatoes – a.k.a., Okinawan Purple Sweet Potatoes or Hawaiian Purple Sweet Potatoes – are a beautiful cultivar, featuring off-white or beige skin with a vibrant purple-pink interior. They’re starchy – more so than their orange-fleshed counterparts – but have no saturated fats or cholesterol.
They were, in fact, a dietary staple of the people in the famous Okinawa Blue Zone (an area designated as having a high number of centenarians).
They are, unfortunately, difficult to find in the typical American grocery store, which is a shame because they’re so delicious and are my very favorite variety of sweet potato.
Taste is subjective, of course, but I find them far less cloyingly sweet than the standard orange grocery store variety (often, Beauregard). Nutty and slightly earthy, they not only make excellent crispy fries, but are also quite lovely in salads (I’m an add-all-the-vegetables kind of green salad fan).
They cook up fairly quickly in a pressure cooker, and my favorite work-from-home vegetarian lunch is one topped with black beans, salsa, and guacamole.
Okinawan Sweet Potatoes retain their color when cooked and, in fact, deepen into a rich, dark purple, while the skins tend to take on the purple coloring.
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:
I tried growing purple sweet potatoes like the Blue Zones…
FAQ
Where can purple sweet potatoes grow?
Purple Majesty sweet potatoes have a 100 day maturity date which makes them a great option for all growing regions. Growers in the northern states love this variety because it has a shorter maturity date, allowing them to get a quality harvest without a long summer.
How long does it take to grow purple potatoes?
| Shipping Weight | 1.5 lbs |
|---|---|
| Soil Temp | 50° F+ |
| Planting Depth | 3–5″ |
| Days to Germ. | 10-20+ |
| Days to Maturity | 60+ |
Is purple sweet potato vine annual or perennial?
Is a sweet potato vine an annual or perennial? Hardy in USDA zones 9-11, sweet potato vine is perennial in warmer climates, but is most often grown as an annual.
Can I grow sweet potatoes in zone 5?
Choosing your sweet potato variety is very important. Sweet potatoes grow in Zones 5 – 11 and grow well in Zone 6, however, some varieties will do much better than others. You might want to grow two varieties to see which does the best for you.
Are purple sweet potatoes cold tolerant?
Purple sweet potatoes prefer hot, humid conditions much like their orange sweet potato cousins. While not cold tolerant, they can adapt to various climates with the right care: Zones 8-11 – These warm zones are ideal for purple sweet potatoes. Plant slips after the last frost when soil temperatures reach 65°F.
When to plant purple sweet potatoes?
Zones 8-11 – These warm zones are ideal for purple sweet potatoes. Plant slips after the last frost when soil temperatures reach 65°F. Zones 6-7 – Purple sweet potatoes can grow well here, but may need season extending strategies like black plastic mulch to boost heat and soil temps. Wait until late spring to plant.
How long does it take to grow purple sweet potatoes?
Planting purple sweet potatoes can be challenging, as they require a long growing season (around 120 days), and consistent, hot weather. To grow your own purple sweet potatoes, check out the following steps: 1. Choose a site. Sweet potatoes need at least six hours of full sun a day.
How do you grow purple sweet potatoes?
To grow your own purple sweet potatoes, check out the following steps: 1. Choose a site. Sweet potatoes need at least six hours of full sun a day. While they can still grow in partial shade, the crop will thrive better with direct sunlight. Choose a planting site that receives at least six hours of sunlight per day. 2. Dig your planting holes.
Are purple sweet potatoes better than orange sweet potatoes?
Purple sweet potatoes are a bit different than the common orange sweet potatoes that we know so well. They have a different texture (heavier and creamier) and they are not as sweet as the orange potatoes. They are very good for us (more on that later), and they are just as simple to grow as orange sweet potatoes.
Can you grow purple sweet potatoes with tomatoes?
This vibrant tuber, often called Okinawan sweet potato or Hawaiian sweet potato, is a real showstopper—not just in appearance, but also in taste and nutrition. But let’s not sugarcoat it. Growing purple sweet potatoes takes time and attention. A lot of it. So, if you’re short on patience, maybe stick with tomatoes.