Are sweet potatoes perennial?

(Julie Bawden-Davis)

Looking for a fun project that kids and adults love? Try growing sweet potato vine indoors. All you need is a sweet potato that’s sprouting, a jar and some toothpicks. And just a tad of patience.

Grow sweet potato vine indoors, and you’ll soon have a sprawling vine with lime-green or purple-tinged leaves. Here’s how to enjoy growing this fun vine as a houseplant.

Get an organic sweet potato. Chemically treated sweet potatoes sprayed with a sprout retardant will be sterile and won’t sprout. Look for sweet potatoes with root nodes (eyes) that appear to be swelling. This indicates that leaves or roots will soon sprout from the nodes.

If you have an old sweet potato you didn’t get around to cooking and it has started to sprout little leaves or roots, even better. It might not be good for eating at this point, but it’s ripe for growing!

Fill a rooting jar with lukewarm water. Choose a vessel that is at least 4 inches deep, so that the roots can grow downwards without obstruction.

Take out some sturdy toothpicks. Beginning two to three inches up from the bottom of the sweet potato, insert the toothpicks at regular intervals.

Insert the sweet potato in the water, so the tip is submerged. Adjust the toothpicks as necessary. In a couple of week, roots will begin to emerge from the root nodes near the water. Leaves will grow out of root nodes at the top of the sweet potato.

(Julie Bawden-Davis)

Place the sweet potato in a sunny location. The leaves require regular light for the plant to grow well. If necessary, supplement with artificial lighting.

Maintain clean water. Twice weekly, empty the water in the sweet potato jar and refill with fresh, lukewarm water. If the water becomes stagnant, the sweet potato may not grow. The water can also become smelly if it sits too long. Avoid using softened water. It’s high in salts, which inhibits rooting and healthy growth.

Move to a larger jar/vase. When the roots have grown full and lush, ensure that they have plenty of room to grow by moving to a larger vessel. Also give the vines room to spread out. You can stake them or let them hang from a high location. When working with the vines, keep in mind that the stems are fairly breakable.

Fertilize. Once a month, add a drop of an organic, all-purpose liquid or water soluble granular fertilizer. Fertilize right after changing the water.

Julie Bawden-Davis is a garden writer and master gardener, who since 1985 has written for publications such as Organic Gardening, The American Gardener, Wildflower, Better Homes and Gardens and The Los Angeles Times. She is the author of 10 books, including Reader’s Digest Flower Gardening, Fairy Gardening, The Strawberry Story Series, and Indoor Gardening the Organic Way, and is the founder of HealthyHouseplants.com. Her backyard is a Certified Wildlife Habitat by the National Wildlife Federation.

The sweet potato plant or sweet potato vine has been cultivated for around 2,000 years for its sweet tasting tubers. It is said that Columbus brought the plant to Europe from the New World on his expedition (Missouri Botanical Garden). Though the variety of sweet potato plant that produces the edible tubers can be planted for its trailing vines, more recently, different variations have been cultivated specifically for their ornamental foliage. The ornamental sweet potato vine is not grown for edible consumption.

It does produce sweet potato tubers, and though these won’t cause any harm if eaten, they tend to be bland and bitter. It is also worth noting that it is ill-advised to eat any element of a sweet potato vine that has not been specifically cultivated for food purposes, without knowing what pesticides may have been used on it that could be harmful when ingested.

Instead of being grown for the tubers, the sweet potato vine is grown for its colorful foliage, which has many uses both inside and outside. It makes an excellent container plant, with its trailing vines falling over the edges of pots in an effortless and attractive manner. It works well as an ornamental houseplant, as well as for yearlong ground coverage in outdoor flower beds. Being very resistant to drought conditions, this plant is popular in the South, where, among other things, it looks great in hanging baskets.

In some instances, lavender flowers can bloom on the vines, but they are generally considered uninteresting in comparison to the foliage of the sweet potato vines. Flowering is uncommon, happening in most instances on older varieties.

Quick Facts

Origin Tropical America, Mexico
Scientific Name Ipomoea batatas
Family Convolvulaceae
Type Herbaceous perennial
Common Names Sweet Potato Vine
Ideal Temperature Above 70° F
Varieties Many cultivars, including Blackie, Marguerite, Solarpower Red, Sweet Caroline, Tricolor, Illusion Midnight Lace, and Illusion Emerald Lace
Light Bright light
Watering Keep young plants in moist soil; mature plants can sustain dry soil between waterings
Humidity High humidity
Pruning Prune to prevent overgrowth when required
Pests Beetles, caterpillars, whitefly, aphids, weevils

Caring for Your Sweet Potato Vine

Watering

The sweet potato vine needs to be in a well-draining soil so that any excess water from rainfall or watering has the opportunity to drain away. This plant doesn’t like sitting in wet soil, so if you have this as a houseplant make sure you remove any standing water from around the base after you water it. When in containers, whether inside or outside, you can fill the bottom of the pot with rocks or large pebbles to help with drainage and prevent the soil from becoming waterlogged.

As a houseplant, this plant will do best if you allow it to go dry in between waterings, but if left dry for too long, the leaves will wilt. Check the soil with your finger to ascertain how moist it is. If it feels damp to the touch, then wait a while before watering it. Outside, you will be at the mercy of the weather when it comes down to watering your plants. Ensure you plant the sweet potato vine in a well-draining soil so that it can cope through periods of heavy rain. If you live in a drier climate, water with a hose or watering can on a regular basis to ensure the plant gets enough moisture.

Mature sweet potato vines fare relatively well in drought conditions. If conditions become too dry, then the plant will sustain its leaves on water from its tuberous root. Unfortunately, the tubers on sweet potato vines do not tend to be very big, so this practice cannot be relied upon for more than a week. If the plant does not receive any external water and has to rely on root moisture, then the leaves will not look as healthy or be in as abundant as before, though it should recover well once the watering frequency is corrected.

Provided your sweet potato vine is mature and in good condition, then it should manage just fine if you fail to water it for a short time, though obviously will be at risk of dying if you neglect it for too long. Younger plants whose roots are not yet well established will need constant water to survive. They like to be in consistently moist soil, though you need to strike a good balance because overwatering will lead to root rot when the plant is in a container. For younger sweet potato vines planted in flower beds, you can help the plant retain moisture by layering mulch on top of the soil, while stays damp for longer than the soil itself.

Light

Sweet Potato thrives in bright sunlight

This plant is a sun worshipper and thrives in bright direct sunlight. This isn’t always possible though, and fortunately, the sweet potato vine will do just fine in a combination of full sun and partial shade. If used as a houseplant, try to home it on a windowsill that benefits from all-day sun.

Temperature

This plant likes to be kept quite warm and can be kept outside all year round in climates that don’t drop below 70° F. It will survive in climates where the nighttime temperature dips to 50° F at its coolest, though any colder than this and the plant will need to be brought inside until warmer temperatures return. If kept inside all year long as a houseplant, the sweet potato vine will be happy so long as it doesn’t get too cold. Usual inside temperatures will be fine, but try to keep it away from cooler areas of the house.

Humidity

This plant, as a native tropical plant, thrives in conditions of high humidity. Watering the soil regularly will help to create humidity around the plant. This plant will not fare well outside in locations that experience low humidity or strong winds. In dry air, the plant’s leaves will quickly lose moisture through the stomata, and this will be further worsened by the fact that it enjoys full sun, which can increase the rate at which the leaves dry out. When this occurs, the plant will suffer from dehydration and become quite unhealthy, eventually dying off. Indoors, you can recreate the plant’s native humidity by spraying it with a water mister. When planted in containers, be sure to grow your sweet potato vine alongside plants that have similar requirements, such as tomatoes. Otherwise, neighboring plants might suffer from the high humidity created for the sweet potato vine.

This plant can become quite unruly if left to its own devices and will benefit from an occasional pruning session. The vines can grow to 10 feet in length, so you may wish to continually cut back the plant to keep at to a size appropriate for the space you have it in. To trim specific areas, use a pair of shearing scissors and cut stems back to around a quarter inch from the node. This will encourage new growth. The sweet potato vine responds effectively to pruning, growing with some force in areas it has been cut back. If growth becomes too aggressive, prune more regularly to keep the plant in check. Frequent pruning will encourage the growth of new flowers.

Propagation can be achieved in two ways: from stem cuttings or directly from a sweet potato tuber.

To propagate from a stem cutting, you will need to cut a stem from a healthy sweet potato vine that has several leaf nodes on it. Remove the leaves on the lower half of the stem, which should be around six inches in total. Place the cutting into a glass of water, and roots should sprout within the space of a few days. This can effectively be done over winter because the cutting will happily live in the water until spring when it can be planted outside or in a container with soil.

To propagate from a sweet potato tuber, you can use an edible sweet potato where roots will emerge from the eyes on the tuber. Put it in a glass of water with the bottom two-thirds of the tuber submerged in the liquid, and from this, the vine will grow. Alternatively, you can put a sweet potato in a cold and dark place over winter, where it will begin to sprout. In early spring, you can chop up the potato into chunks, ensuring each chunk has one sprouting eye. Plant these directly into soil to grow new vines.

Varieties

Illusion Emerald Lace

Illusion Emerald Lace Ipomea – Credit to agrilifetoday

This variant of the sweet potato vine has been cultivated for its vibrant green foliage. The deep-cut leaves are splayed out in almost a star shape, creating a very visually attractive plant. Spreading 4 feet across and 10 inches in height, this plant is sizeable, creating a quite an impact.

Blackie

Ipomea Blackie at the bottom of the photos – Credit to daryl_mitchell

The leaves of this plant have five points in the shape of a hand. The foliage is a very dark purple-black, looking quite striking when set amongst green plants. This variant grows vigorously and is best kept outside to allow full growth. In a hanging basket or container, it will need frequent pruning throughout the summer months, when it can grow several feet a week if the conditions are ideal.

Illusion Midnight Lace

Illusion Midnight Lace –stickpen

This sweet potato vine variant can look quite spooky in its dark purple shade with almost spiky looking leaves. It has a compact trailing and mounding habit, growing to around 4 feet wide and 10 inches in height.

Marguerite

Ipomoea batatas ‘Margarita’, ‘Marguerite’

This is an especially popular variant due to its heart-shaped leaves and bold chartreuse foliage with a subtle golden hue. The colors will remain bright all year round, helping to bring a lightness to your garden that is generally only experienced in spring and summer.

Sweet Caroline

Sweet Caroline

This variant of the sweet potato vine comes in a selection of colors, including kiwi, lime, purple, and even jet black. The black variety features heart-shaped leaves, which make quite a statement in the black color. For a brighter look, the lime colored leaves give a vibrant tropical feel. The Sweet Caroline vine grows less aggressively than some of the other vine variants, making it ideally suited to planting in container pots. It usually grows to a more compact size than its other close relations, and therefore may be a good choice for anyone who isn’t keen on tirelessly pruning back their plants.

Solarpower Red

Spreading to three feet, this vine is slightly more compact than others and features rusty bronze-colored foliage. Its leaves have dense coverage, so it looks fuller and lusher than some other vines. It won’t get leggy or spindly, even in old age, and makes the perfect trailing plant for hanging baskets and containers.

Tricolor

Ipomoea batatas Tricolor – Credit to starr-environmental

This striking variant features variegated foliage in shades of green, white, and pink. The plant is more compact than other sweet potato vines, with small leaves in a pointed shape.

Potato Beetle resting on the leaves of potatoes

Beetles

Many types of beetle are attracted to this plant, including the Golden Tortoise Beetle. This insect, although very attractive as insects go, can wreak havoc on your sweet potato vine. The beetles look like tiny drops of golden molten lava, with an almost iridescent quality. Though they are certainly interesting to look at, you will soon be sick of the sight of them when they start munching on the ornamental leaves of your sweet potato vine. A golden tortoise beetle infestation can completely destroy the look of your plant, leaving obvious holes all over the foliage.

Cucumber beetles are also a pest for sweet potato vines. These beetles have yellow bodies and are dotted in black spots of feature green stripes.

Flea beetles, which can be identified for their long hind legs and tiny size, also cause issues for the vines. The larvae of both the cucumber beetles and flea beetles chew tiny holes in the plant that will lead to disfigurement of the root.

To rid your plant of beetles, a pesticide such as pyrethrum, will control the problem. Alternatively, for a safer option, you can introduce a natural predator of the beetle, such as tachinid flies. Neem oil is also a natural yet effective way of dealing with beetles.

Whitefly

Silverleaf whitefly and aphids suck on the leaves and stems of the sweet potato vine, draining the plant of its nutrients. They gather in groups on the plants surface, where they excrete a sugary liquid after sucking the sap from the plant. The sugary liquid will soon seem to turn into a black powdery substance, which is actually mold developing on the plant. When this covers the leaves, it will create a barrier for photosynthesis, and the leaves of the plant will die as a result.

These types of pest can be controlled by lady beetles, which are the natural predator of whitefly and aphids, or you may wish to try to remove the insects by hand (Plant Village).

Caterpillars

Several types of caterpillar can prove problematic for the sweet potato vine, including armyworms, cutworms, and leaf miners.

As the name suggests, leaf miners feed on the inside of the leaves where the soft tissue is. Leaf miners are a moth caterpillar, which is gray when they develop into a moth. The moth will lay white-green colored eggs onto the surface of the vine’s leaves, which then turn into brown pupae. The tiny pupae can sometimes be spotted on the underside of the leaves. Once transformed into a caterpillar, the leaf miner will be around a quarter of an inch in length. As it mines along the surface of the leaves looking for its next feeding spot, it will leave a silver trail which will soon turn brown. The marks left behind by the caterpillars will make the plant look unhealthy and unattractive, and the damage caused can also affect root growth.

Caterpillar populations can be controlled by natural predators, such as ants, but a severe infestation may require more direct treatment. Bacillus thuringiensis is a bacteria that can help to rid your sweet potato vine of caterpillars.

Weevils

This incredibly destructive pest feeds on all parts of the sweet potato vine, but it is in the roots where it will cause the most damage. The larvae, which are white with brown heads, feed on the roots, creating tunnels through the root structures. In doing so, the plant’s health is compromised, and a stunted plant with wilted or dead leaves will be the end result.

Sweet Potato Vines — The Best “Spillers” Ever

Anyone who’s gardened in containers for long knows the magic formula — for an effective container, you need a “thriller” (upright, showy plant), “fillers” (mounding plants on the sides), and “spillers” (trailing plants that cascade over the sides). And there can be no doubt that the most popular thrillers of all are the many selections of sweet potato vine.

Closely related to real sweet potato, sweet potato vines (Ipomoea batatas) don’t form edible tubers. But who cares? Their eye-popping foliage creates a splash of bright color faster than just about any plant I know. The leaves can be yellow, chartreuse, burgundy, nearly black, red, light green, or variegated. They can be three-lobed, heart-shaped, or deeply cut like a Japanese maple leaf.

If memory serves, the first two selections offered were the bright chartreuse ‘Margarita’ (‘Marguerite’), above, and the deep purple ‘Blackie.’ These extremely vigorous plants grow 8-10 feet or more in a single growing season, so you often see them planted as a seasonal ground cover. Next in line came ‘Ace of Spades,’ featuring heart-shaped, purple leaves.

Image zoom em’Ace of Spades.’ Photo: a href=

It’s a little less rampant than the first two, although 6 feet of growth in one season isn’t out of the question. I like it a lot more than ‘Blackie.’

These first three selections need pretty big containers, lest they conquer and kill pretty much all of their thriller and filler companions. Fortunately, there are options, like this one.

Image zoom ‘Goldfinger.’ a href=

‘Goldfinger”offers deeply cut, bright chartreuse leaves. It spreads only 24-36 inches. And thanks to the breeding work done at North Carolina State University, we now have the compact-growing Sweet Caroline Series and the Illusion Series as well.

Image zoom emSweet Caroline ‘Raven.’ Photo: a href=

How do you like Sweet Caroline ‘Raven?’ It’s bushy and compact, growing only 2 to 4 feet. This is such an improvement over the older ‘Blackie’ that ‘Blackie’ should go into voluntary exile before it is sent by force to North Korea.

Image zoom emIllusion ‘Garnet Lace.’ Photo: a href=

How about Illusion ‘Garnet Lace?’ Wow! I love the color. I love the finely cut leaves. But I do not love it more than my wife. That would be wrong of me. This one spreads 2 to 4 feet.

How To Grow Sweet potato vines like heat and sun. The more they get, the better they do. They’ll grow in light shade, but their colors will be duller. Give them moist, fertile, well-drained soil. Plants in containers should be goosed with liquid fertilizer every two weeks. They’re winter hardy as far north as USDA Zone 8. ‘Margarita’ and ‘Blackie’ form large tubers you can dig and save over winter in colder zones, but the others do not.

The most common problem people experience with sweet potato vines is discovering leaves riddled with holes. This is the handiwork of the sneaky golden tortoise beetle. ‘Margarita’ is its favorite. To control this pest, plant a different selection or spray your plants according to label directions with neem oil or spinosad.

Ornamental Sweet Potato

The ornamental sweet potato is a bold tropical plant that grows as a perennial in Florida. The foliage is much more colorful than that of edible sweet potatoes.

This unique plant is popular for containers and borders. In a container, the vines will quickly flow over the edges. In beds, it’ll behave as a groundcover. It can easily be trimmed when it gets too wild, and the cuttings can be used to create new plants.

Other than an occasional trimming, ornamental sweet potato is an undemanding plant. The vines will let you know when they need water by wilting, and the foliage quickly springs back from a frost or freeze. It prefers full sun, but will grow in partial shade.

This hardy, drought-tolerant climber comes in a wide array of attractive foliage colors, from bright chartreuse green to a purple so dark it’s almost black.

UF/IFAS Publications

  • Perennial Gardening in Florida
  • Sweet Potato Vine–UF/IFAS Extension Nassau County

Also on Gardening Solutions

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  • Versatile Vines

Potato vine beetles to the rescue

“I just go down and collect the potatoes and those are the seeds. It prevents new ones from growing. They fall on the ground, they root, they grow a tuber underground and sprout up from the tuber.”

That’s why just cutting down the vine isn’t enough. If the little potatoes that fall all over are not picked up, the vine will just keep growing and spreading.

“Now the potatoes are getting big and falling off,” Heare said. “I go down and collect as many as I can.”

Steve Giguere, park manager at Koreshan, is trying to stop the spread with the release of air potato beetles.

“It eats the leaves,” Giguere began. “It helps slow it down. It’s biological control researched by the University of Florida.”

Giguere said it is important to get rid of the vine.

“If left unchecked it takes over the canopy of trees,” he said. “It will take over the understory by shading it out. It also damages the trees.”

Giguere said one problem is that kids will pick them up and throw them around and that spreads the vine to other places. The potato vine isn’t limited to state and national parks. It is in backyards all around Southwest Florida.

Doug Caldwell, Commercial Landscape Horticulture, and Landscape Entomologist with the University of Florida Extension service said the quick growth takes people by surprise.

“Once the rainy season starts it starts growing and people start noticing it,” he began. “We had a pretty mild winter that the air potato really likes. It doesn’t like it when we have cool temperatures.”

Caldwell said trying to cut it down or spray it is quite difficult. He recommends releasing an air potato beetle.

“People can send a form in and get some beetles,” he explained. “It seems kind of remarkable. In some northern counties around Gainesville they went back 6-12 months after the release and they are claiming 98 percent control.”

Richardson said the vine is so hardy it does not need much to grow.

“An air potato is nothing but energy,” he began. “Put it in your closet and it won’t rot and it will grow very well in the dark in your closet. You will wake up one day and you will have a six foot vine in your closet.”

Potato vine beetles

Doug Caldwell, Commercial Landscape Horticulture, and Landscape Entomologist with the University of Florida Extension service, recommends releasing an air potato beetle to stop the spread of potato vines. For more information and to order potato vine beetles, go to

Last year’s leftover sweet potatoes are sprouting by spring and ready to become this year’s crop.

What’s more effortless, rewarding, nutritious, delicious and fully sustainable than growing sweet potatoes in Florida? They’re easy to grow, thrive in our hot summers, require little water and store for months. They’re delicious and high in nutritional value. Once they’re started, you’ll have everything you need to grow them year after year. Yep, I’m a big sweet tater fan.

Years ago a friend gifted me with a handful of slips. My Mom and I each planted some, teasing each other about whose crop would produce the best yield. She planted hers like her grandparents did – at the top of high dirt mounds. I planted mine all crowded together in a flat area. We both won the competition because this plant thrives no matter how you plant it or care for it. We ate our taters all winter and into the spring retelling the story of our competition.

So, it doesn’t matter how you do it – just plant some! You can’t go wrong. Here’s what I’ve learned so far. Admittedly I’m a sweet tater novice who hates sweating in the heat, so it’s full of short cuts. Perhaps some of you experts will tell us the “right” way to master this crop. But trust me, my lazy way works.

GETTING STARTED

You can get started from sweet potato slips purchased at local feed stores. Or from tubers and vines from a friend who grows them. If you’re working with tubers left over from last year’s harvest just cut them into cubes, making sure every section has an eye or sprout. Both slips and cuttings go directly into the dirt ideally between March and June. I planted some in late July once and still had a banner yield. They like loose, well-drained, sandy soil.

GROWING

Sweet potatoes thrive in our hot North Florida summers with minimal care or watering. But keep the vines trim or they’ll take over! Don’t forget you can eat the leaves too. Super healthy!

In a few weeks, green sprouts will pop up. Over the weeks and months they produce luscious vines with beautiful purple flowers. Make sure you give them plenty of room for expansion because the vines spread quickly, taking over anything in their way. In previous years I watered them daily. Silly me. Now I realize they don’t need any water or care. Even in the 2011 heat and drought, they thrived in full sun! I don’t even fertilize them, but then I plant everything in my homegrown, rich, organic compost.

HARVESTING

In the fall, check on them. Dig up an area by hand to see if they’re ready to harvest. Or wait for the leaves to turn yellow from the first frost. I find they’re quite flexible on harvest time. I left some in the dirt one year until the first frost turned all the leaves black. I dug them up immediately to find they were even sweeter and tastier than usual. Some people harvest using a spading fork. But be gentle because they spoil quickly when bruised. I like to sit by the garden bed and dig them up by hand. I find it fulfilling. Harvesting is easiest when the dirt is dry.

CURING AND STORING

Let your taters dry in the sun on top of the bed for several hours (or days). If you like, you can gently wipe off the excess dirt. Just be careful not to bruise them. I find they store longer when I don’t wipe off any of the dirt. You can eat them fresh out of the ground, but they get sweeter when fully cured. It helps heal some of the harvest injuries and prepares them for long-term storage. They’ll develop thick skins that help them store for months! I put my harvest in newspaper-lined boxes, then place the boxes on my back deck out of the sun for a week. Then I move them to my garage. Perhaps someone could tell me how to create a makeshift root cellar!

Roasted sweet potatoes with sautéed greens.

EATING

Both the roots and leaves are loaded with nutritional value and oh so very delicious. Oddly, I’m not crazy about baked sweet potatoes, so each year I experiment with new recipes. You’ll find some recipes posted here. My all-time favorite is roasted! I select the smallest ones and scrub the skins really well. Some need to be cut into bite-sized pieces. I put them in a large mixing bowl with other garden goodies (onions, leeks, garlic, fennel bulbs, baby carrots, broccoli, cauliflower, etc). Coat them with olive oil and whatever fresh are growing (rosemary, cilantro, basil, oregano, thyme, etc – plus sea salt and pepper). Let them marinade for minutes or even hours. Then I roast them on a 350 degree preheated cast-iron skillet in my oven for about 30 to 45 minutes, turning every 15 minutes or so. With every bite, I’m glad I spent the little effort required to grow them!

Don’t forget the leaves are also edible. I put them in green smoothies all through the hot summer months when most other greens aren’t growing. Some people sauté the leaves, but I’m not a fan of that. I don’t know what my hens would do without the abundance of sweet potato leaves and Okinawa spinach – the only greens that thrive in our garden during the relentless summer heat.

NEXT YEAR’S CROP

Each year I set aside the ugliest, least desirable tubers to create next year’s crop. By late spring they’ve sprouted. I cut them leaving an eye on each piece and stick them in the ground. Often I don’t need to plant tuber’s because the area where I grew them last year is full of volunteers. Often I give both tubers and volunteers to friends so they can start their own tater patch.

Purple flowers in my sweet potato patch

In tropical regions they grow year round in permanent patches making a beautiful ground cover. I tried growing them year-round here, but didn’t like digging up monster-sized, tough, old potatoes. And I even attracted some root pests that ate holes in my taters. So, now I’m back to harvesting as I want to eat them throughout the fall, then digging up the entire plot after the first frost. I turn under the vines so they’ll grow again on their own.

How easy is that? They’re the ultimate, sustainable crop for a lazy Jacksonville gardener like me.

Boiled sweet potatoes mixed until smooth and baked with a delicious topping of brown sugar, cinnamon, and oats, –or– fresh sweet potatoes cubed and roasted with just a bit of olive oil and sea salt. Oh my goodness, fresh sweet potatoes are a treat! My whole family looks forward to harvesting and devouring the delicious root vegetable. My son says that harvesting sweet potatoes is like a treasure hunt. “You never know how many potatoes there will be, or what size they will be.” My daughter says that she just likes to “dig and dig and dig.”

Not only are sweet potatoes delicious, they are considered one of the most healthy foods as they are an excellent source of vitamin A (214% of your daily value), and very good sources of vitamin C, vitamin B6, manganese, copper, and pantothenic acid, among others. Anthocyanin (a color-related pigment) in sweet potatoes is equally valuable for it’s anti-inflammatory health benefits. Okay, you get the point. Sweet potatoes are delicious and healthy. But, can we grow them here in MN or in other cool climates?

Well, I’m so glad you asked! Yes, of course you can, but it takes just a little more work. Sweet potatoes are tropical plants, so they like hot weather, hot soil, and are very sensitive to frost. Here in MN, we have cooler weather with shorter growing seasons, so we need to do a little extra work to ensure that our sweet potato plants are happy enough to grow those delicious and healthy tubers. So, here it goes:

Starting Slips

Starting a sweet potato plant is probably one of the most easy and inexpensive vegetables to start. You do not start sweet potato plants from seed like most vegetables, you start them from what is called a seed potato (a firm sweet potato that is 1-2″ in diameter). Poke two to four toothpicks into the center of the sweet potato (on opposite sides), place the sweet potato halfway into a glass jar, and fill the jar with water until 1-2″ of the bottom of the sweet potato is submerged in water. Place the sweet potato under a fluorescent light (for up to 14 hours per day) or in a bright window. You will soon see roots starting to form on the submerged portion of the sweet potato followed by what are called sweet potato slips or shoots sprouting from the upper part of the sweet potato. Once the slips are 4-5″ long, gently twist or pinch the slip off of the sweet potato right where it connects to the sweet potato and place the slip into a jar of water until roots form (do not submerge the leaves as they will rot).

Preparing the Garden

As far as soil quality goes, sweet potatoes are very forgiving. They don’t need nutrient-dense soil. In fact, too much nitrogen will cause too much foliage growth which will inhibit tuber or root develop. So, if you do fertilize, choose a fertilizer with lower amounts of nitrogen. Also, sweet potatoes can have trouble in soil that contains a lot of clay (which is one of our problems here) by growing skinny and misshapen roots. If you have a lot of clay in your soil, a raised bed can do wonders for those sweet tubers.

Heat! Sweet potatoes love heat. The more 100F days, the better as far as sweet potatoes are concerned. The slips also love to be planted in warm soil (75F soil or warmer is best). To achieve that here in MN, we cover our raised bed with clear plastic sheeting and tuck the sides down between the bricks and the soil for a few weeks before we plant. Also, sweet potato plants do not like temperatures below 55F, so we typically plant 2-3 weeks after our average last frost date. June 1st is a good estimate of the time we typically plant sweet potatoes here in Minnesota.

Once the sweet potatoes are ready to plant, you can make slits in the plastic sheeting (we like to make a cross with slits about 3″ in length), poke a couple of finger down into the soil, and gently lower the slip down into the hole.

Feel free to plant slips all the way to the top leaves as sweet potato slips will grow roots on the entire plant stem if plant in the ground. Fill the soil in around the plant and water (we find it easiest to lay a soaker hose under the plastic before planting). We started our slips pretty early this year, so we did plant some slips in 4″ pots indoors. Because of this, we planted these sweet potato plants before re-applying the plastic as large holes in the plastic would have been needed to plant, thus causing a lot of heat to escape throughout the season.

Once planted, the slips should be watered every day for a week. Once the plants are established they will need about 1″ of water per week until 2-3 weeks before harvest time.

Harvest Time

Sweet potatoes usually mature in 90-100 days. Harvest them when leaves start to turn yellow, and/or before the threat of frost occurs. Two weeks before harvesting, discontinue watering, as harvesting is much easier in dryer soil. When you are ready to harvest, gently dig around the sweet potato plant with a pitch fork or shovel trying not to pierce the tubers. Digging works best when you start on the outside of your garden and work inward toward the center. Sweet potatoes need to cure if you want the best sweet, rich, sweet-potato taste. Perfect curing conditions are 90% humidity with a temperature of 85F. After two weeks of curing, sweet potatoes are best stored in cool, dark areas with temperatures between 55F and 60F and humidity at 85-90%. Unheated basements work well for storage, and sweet potatoes should store for six months or more! We still have perfectly edible sweet potatoes in our basement that have been stored for nine months now. Talk about a long shelf life!

Go ahead and try growing sweet potatoes, even if you live in cooler climates! The resulting harvest is one of delectable deliciousness and longevity (if you don’t eat them all right away). Happy planting!

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