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Growing Sweet Potatoes
Planting, Growing, and Harvesting Sweet Potatoes
Planting, Growing, and Harvesting Sweet Potatoes
Bonnie Taylor Barry/Shutterstock
Sweet potatoes are grown more often in southern regions because they require at least four months of warm temperatures, though there are varieties that will grow in northern gardens, too. They are surprisingly easy to grow and just a few plants can produce a generous harvest. Here’s how to plant, grow, and harvest delicious sweet potatoes in your garden.
In warm climates, many gardeners plant sweet potatoes about a month after the last spring frost, when both the air and soil are dependably warm. There are bush types and vining types.
Sweet potatoes aren’t started by seed like most other vegetables, they’re started from slips—small rooted pieces of tuber which are sliced right off the sweet potato.
Not only are sweet potatoes very easy to grow, they are also drought- and heat-tolerant, and have few pests or diseases. The sweet potato is very nutritious and relatively low in calories.
Planting
How to Plant Sweet Potatoes
- Sweet potatoes are typically grown from slips, which are sprouts that are grown from stored sweet potatoes. You can buy slips from garden centers, nurseries, or local farmers.
- You can also create your own slips to plant in the spring. In November (this is when the best of the new harvest will be out), go to your supermarket and look for unblemished and uncracked medium-size sweet potatoes. One sweet potato should yield about 12 plants.
- Store sweet potato slips in a well-lit room with a temperature between 65° and 70°F. Keep them there until about 90 days before the last spring frost date. They will then need to be embedded in soil for 90 days and kept continuously warm and moist.
- Use a 1-½ gallon pot for every two slips. Remember to poke drainage holes in the bottom of the pot and fill it with 3 inches of mulch, followed by garden or potting soil. Plant the slips in the pot at a 45° angle so that the sprouts will grow above the soil. When the slips are 6 to 12 inches tall, you can plant them outdoors, as long as all danger of frost has passed.
- After you have grown your own slips or bought them, till the area of the garden you will be using to a depth of 8 to 10 inches. Create raised mounds 6 to 8 inches tall and about 12 inches wide. Use fertile, well-drained soil.
- Plant the slips 12 to 18 inches apart in the bed, after the last spring frost date. Plant the slips deep enough to cover the roots and about ½ inch of the stem. Water the slips with a starter solution (a liquid fertilizer) that is high in phosphorous, then water generously for a few days to make sure that the plants root well.
- See more tips for growing sweet potatoes.
Care
How to Grow Sweet Potatoes
- Side-dress the potatoes 3 to 4 weeks after transplanting with 3 pounds of 5-10-10 fertilizer per 100 feet of row. If you have sandy soil, use 5 pounds.
- Hoe the beds occasionally to keep weeds down. Remember to reshape the beds with soil or mulch.
- For good harvests, do not prune the vines, because they should be vigorous.
- Remember to keep the plants watered. Deep watering in hot, dry periods will help to increase yields, although if you are planning to store some of the potatoes, do not give the plants extra water late in the season, as it could cause cracking of the tuber’s skin.
Pests/Diseases
- Flea beetles
- Sweet potato scurf
- White blister
- Fungal leaf diseases (Alternaria leaf spot and blight, Botrytis)
- Stem rot
Harvest/Storage
How to Harvest Sweet Potatoes
- You can start digging up the potatoes as soon as they are big enough for a meal. Often, this is 3 to 4 months from when you planted the slips (most varieties take at least 100 days to reach maturity).
- Usually, sweet potatoes are ready to harvest when the leaves and ends of the vines have started turning yellow, but you can leave them in the ground up until the fall frost.
- Since the roots spread 4 to 6 inches deep in the soil, a spade fork is useful when digging up the potatoes. Loosen the soil around the plant (18-inch diameter) so you do not injure the tubers. It’s fine to cut some of the vines away.
- Pull up the primary crown of the plant and use your hands to dig up the tubers. Handle the sweet potatoes carefully, as they bruise easily.
- After digging up the tubers, shake off any excess dirt, but do not wash the roots.
- You must cure sweet potatoes or they will not have that delicious, sweet taste. Curing the potatoes allows a second skin to form over scratches and bruises that occur when digging up the potatoes. To cure, keep the roots in a warm place (about 80°F/27°C) at high humidity (about 90%) for 10 to 14 days. A table outside in a shady spot works well. For best curing, make sure that the potatoes are not touching one another.
- After curing, throw out any bruised potatoes, and then wrap each one in newspaper and pack them carefully in a wooden box or basket. Store the sweet potatoes in a root cellar, basement, or other place with a temperature of at least 55°F/13°C.
- If stored at a temperature range of 55–60°F (13–15.5°C) with high humidity, the tubers should last for about 6 months. When removing the potatoes from storage, remember to be gentle; do not dig around or else you will bruise the potatoes.
Recommended Varieties
- ‘Centennial’ is one of the most popular types of sweet potato. It is carrot-colored and has a good storage life. It is also a good producer for northern growers.
- ‘Beauregard’ originally comes from Louisiana, but grows well in the north, too. It has light purple skin and dark orange flesh.
- ‘Jewel’ is copper-colored and has good disease resistance. It also has a good storage life.
- ‘Bunch Porto Rico’ is a good choice for gardens with limited space. It is copper-colored and very flavorful.
- ‘Stokes’ offers a vibrant purple color and is full of extra health benefits.
- ‘Vardaman’, another good choice for gardeners with limited space, is a bush-type variety with golden skin and orange flesh.
Wit & Wisdom
- Sweet potatoes will retain their color better if cooked with a slice of lemon.
- Sweet potatoes are a very healthy root vegetable, and they provide many benefits. Here’s why you should eat sweet potatoes.
- Did you know that sweet potatoes and yams are different crops? Here’s an explanation of the difference between the two plants.
Recipes
Cooking Notes
Check out our ten best sweet potato recipes!
To the cook, sweet potatoes are easier than pie (or sweet potato pie!).
- They can simply be scrubbed, poked with a fork in a few places, and baked at 400°F for 35 minutes to one hour, until they give a bit when you squeeze them in your pot-holder-protected hand.
- In the microwave, a whole sweet potato baked on high should be ready in 4 to 6 minutes. It may still feel firm when done; let it stand about 5 minutes to soften.
- Sweet potatoes can also be steamed whole (cleaned and unpeeled) for about 40 minutes or until tender, or cooked whole (cleaned and unpeeled) in boiling salted water for about 35 minutes. (Boiling reduces the flavor considerably.)
- Immerse cut raw sweet potatoes in water until you’re ready to cook them; they will darken otherwise.
As a general rule, don’t substitute sweet potatoes for regular potatoes in recipes; the two aren’t related. Sweet potatoes don’t hold together the way potatoes do, and their strong flavor can overwhelm a dish meant for a milder potato taste. Sweet potatoes are also not related to yams. But they make a fine substitute for pumpkin, especially in desserts.
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Reader Comments
Leave a Comment
Growing sweet potatoes
Although I haven't tried this yet, I've heard that you can plant regular potatoes in old tires, stacked atop one another & filled with dirt; to minimize space I would assume.
My question is, can sweet potatoes be planted this way as well?
old tires as containers
The idea of using old tires as planters is not something we can get behind (recommend), Sure, some sources suggest that they are safe short term (biodegradation being a long term process) and they are harmful if they have been burned or are shredded for use. It just seems that there are so many things that can be used as containers why get tires involved. In terms of growing habit, sweets do not grow like “regular” potatoes; it is not necessary to stack dirt up around sweets.
Growing potatoes etc in tires
I read that vulcanised rubber contains high levels of heavy metals and other toxic compounds. I don't know whether they would definitely leach into soil and plants but I would avoid using tires for growing anything.
Eaten sweet potato slips
We planted sweet potato slips and half of them were eaten, rabbits. A few of the nibbled vines still had a slight green slip poking out of the ground. Will the slips die or continue to grow?
afer rabbits...
Try to protect the remaining slip; cover them carefully with screening or something like (but closer woven than) chicken wire. The slips might make it. It’s still early in season.
What are these?
I've had this potato patch for over a year. I decided to dig it up today. March 30, 2019. They are really small, very hard and white. What are these?
Sweet Potato slips
I'm new at this. I halved a sweet potato and placed the exposed surface in a glass with water. They sprouted beautiful leafy green stems! The stems are bushy and maybe 6 inches long now. Did I wait too long to plant them in the soil? If I twist them off, I fear breaking the stem and roots. Can't I just carefully slice around each stem and try to not disturb the roots- planting the slip with a margin of original potato around it? Thanks!
Need help with Sweet Potato problems
I harvested my first crop of back yard sweet potatoes today, Houston area. Late harvest, I know. They have been in since May and it is been too wet. Some of the sweets looked like they have ridges, other look bit. I saw grubs in my bed and will take steps to treat them.
My question - what do I do with the damaged potatoes? If I can remove the portion of the potato with the damage, are they safe to eat or cure for slips for next year?
damaged sweets
If these were our sweets we would cut out the damaged area and proceed as normal—eating them or slipping them. BTW, you’re in good company: Did you know that Texas is the fifth largest producer of sweets in the United States?
It’s unfortunate that the grubs got to the sweets before you did. We looked for a solution and this Louisiana State U Ag Center site has some advice: https://www.lsuagcenter.com/portals/our_offices/research_stations/sweetp...
Because one of the most common problems is soil, we checked the Texas A&M site for soil advice specific to your state. You might find it helpful: https://agrilifeextension.tamu.edu/browse/featured-solutions/gardening-l...
Here’s to a better harvest next year!
Sweet potato slips
I cut a sweet potato from last year's crop and suspended both halves in a jar of water. Each half produced a number of slips; 50-75 in total. I planted the slips in our community garden and had a great harvest. The original potato halves were left outside in water throughout the summer. They made it through to the fall when one was eaten by a chipmunk. I took the second one inside, cut the bottom off of it, and placed it back in water. It immediately began producing roots and slips are starting to sprout.
Can I expect this potato to continue producing slips? Will they be of any value if they make it to the spring? They're doing all this in November as the days grow shorter.
slip upon slip
Jim, it sounds like you have found the eternal sweet potato. If a slip is a slip is a slip, those that your tuber is producing should be fine—if they make it to spring. That could be the challenge. To be on the safe side, get an organic sweet later in the year and start the process again for next season’s plants.
Sweet Potato
I live in California, Is it good to plant sweet potatoes here or not?
Also, i'm in the central valley.
Thanks, Thomas
sweets in Central Valley?
Assuming the conditions of soil, water, and weather are suitable you should have no problem.
Sweet potato problem
We had too much hard rain in south Texas that washed the soil off the top of my sweet potatoes. They're not ready to harvest yet. Should I cover them with soil for the next month? Thanks
Sweet Potatoes
Yes, get them covered again as soon as possible, then check back in on them when they’re due to be harvested!
Sweet Potatoe
We planted our sweet potatoes the 3rd of June, due to the rainy Iowa weather we could not harvest until Oct. 13th. The average size of each potatoe is approx. 6 lbs. and a lot of them are 10 lbs. each. They are way to huge, bit the flavor is good. Would they have been a lot less in size if harvested a month earlier? Thank you.
sweet potato seeds
I bought some sweet potato seeds from Amazon last year but when they arrived there were no instructions as to how to start seeds. Can you help me with instructions as it is time to get going this spring?
sweet potato slips
We are not familiar with starting sweet potatoes from seed and your purchase was unfortunate. In the same way that white (and blue and red, etc) potatoes are grown from seed potatoes (small spuds grown specifically to be planted for later harvest), most people grow sweet potatoes from small sweets, which are called “slips.” We are guessing that it could take a few years for seeds to develop (and maybe you want to try that) and recommend that you purchase slips to insure that you get a harvestable crop. These, like seed (white) potatoes, are set in the soil. See above for more specific growing information.
Curing and Few potatoes, but great vines question answered
For curing Sweet Potatoes, remember that 80 degrees with high humidity is the ideal, but not a exact requirement. In order to store them in the cool you need to time your harvest to that time of the year that is cooling off in your region. Otherwise your are trying to cure them in 90-100 degree weather or if too late in the year, 30-50 degree weather. I harvest mine when the weather is starting to change in October (NE Louisiana), when some days are in the low to mid 80s. After you have dug them up, DO NOT wash them. This removes healthy bacteria and opens them up to fungus decay. Let them dry outside under a shed (out of the sun and rain) for several days. This helps get them dry. Then transfer them to a storage room or a room in your house that stays around 80 degrees or fluctuates in the 60-90 degree range (I keep mine in an outside storage room spread out on racks or on the floor). If you mist stack them, try not to stack them more than two deep, as their skin contact slows the drying process and promotes fungus growth. For humidity I keep a couple of five gallon buckets of water with wet towels around the edge of them or hung up above them. Saturate the towels every day. The evaporation will add humidity to the room. The curing process may take ten days or it may take 30 depending on your situation. When the skins are no longer easily scraped off, they are cured. By then the weather will be cooler and I keep them in the same storage room (with NO water or wet towels). My winters here are mild, but the temperature in my storage room varies from 75-30 degrees throughout the winter, and mine store fine for 6-8 months. I have repeated this process for many years. Remember, our ancestors grew and stored these potatoes with very little temperature and humidity control, and they did fine. Regarding the question of having great looking vines but few potatoes, first I would get a good soil test done, but as they were grown in a raised bed, too much Nitrogen may be the problem, as excess N will tend to put more growth into the vines than the roots. Same thing goes for peas. I hope this helps. Happy gardening.
Growing slips
I put potatoes in glass jars supported by tooth picks,when slips get long enough I then break them off and put them in another jar to root.
A bit different way for sweet potatoes
We have 1/4 acre garden. It's a major amount of work. So we cut corners where we can to save time. I start sweet potatoes in March, 60 days ahead of planting. I pick out tubers from last years harvest, usually medium size, although this is a good way to use small ones that are still good. I stick 3 toothpicks around the sides and suspend the tubers vertically in a jar (like pints) of water, halfway in and halfway out of the water. In a few days, the tubers will start to sprout roots and slips. When the slips have 4 leaves, clip them off and put them in another jar of water 1/2 full. The slips will begin to grow roots, when the single roots start to have small branches on them, take them out of the water and plant them in dirt in a container. I use tapered slick "dixe" cups, because you do not need drainage holes (no mess) and the slick cups make getting the plants out easy. I reuse the cups as long as they aren't severely broken. For the last plants, I just plant the whole tuber. In the garden, I hill up two ridges 3 to 4 feet apart and as long as the number of plants. I usually plant 50 plants, each plant about 16" apart. Water well as needed, if you get twisted curly tubers, that usually means not enough water. I usually harvest in late September (SW Missouri) with a potato fork. After the weather turns cool, they don't grow much, and in October sometimes the mice have a tendency to munch on the tubers, then the garden snakes follow and munch on the mice, and then it makes for fun digging, but hey the snakes are doing their job. I really like the variety that I grow, I do not know what it is, my mom started growing it 30 years ago, after trying several different varieties, and we still got it. It's "best" characteristics is good size, high production, great taste, fine grain and the tubers grow underneath the original plant. Nothing more frustrating than digging taters that are all over the place. Production is usually 10-12, 5 gallon buckets. After harvest, I spread them out on the lawn and hose the dirt off them. I let them dry and put them into paper sacks and then into the big pantry in the game room. Winter temperatures there are probably in the 65-70 degree range. They keep until the following year, and then we start all over again.
Curing in cool climates
Hi,
I grew sweet potatoes two years ago and was unable to cure them due to harvesting them in November when the temperature is cool and air is dry. Is there a way to cure them for 10-14 days in this northern environment? My basement is humid but not 80-90%. I don't think I could leave them in a bathroom with a small heater for 2 weeks. Any other alternatives?
Thanks
curing sweet potatoes
Sweet potatoes have thin, delicate skin that is easily damaged. Curing not only adds a little sweetness, but also allows time for cork to form over injuries, thereby lessening the chance of rot, and prevents the tuber from drying out. This process will take longer at lower temperatures, thereby increasing the chance for diseases to enter any wounds; humidity lower than about 70 percent also will slow healing and affect tuber quality. Gardeners have come up with some clever ways to provide the necessary heat and humidity. Some people do indeed use a small heater in a small room (such as a bathroom) or shed, with a source of humidity, such as a pail of water or a humidifier (or in the bathroom, running the shower every so often). You’d need to monitor the temperature to make sure that it doesn’t get too hot or cold. If you have a greenhouse, then that also would be an option. Some put the potatoes in slatted or cardboard boxes covered loosely with plastic bags (make sure the plastic has a few holes so that there is some ventilation but still a humid environment), and place them in the furnace room or near a small heater. Garden author Nancy Bubel once wrote that she cures her sweet potatoes by simply spreading the potatoes behind her woodstove and covering them with a well-wrung-out towel. Hope this helps!
We have been growing sweet
We have been growing sweet potatoes in a raised bed for the last few years and getting great crop(~100 lbs) every year, until this year. We dug up our bed today and found only a few (~5 lbs) sweet potatoes.
We are puzzled by what happened to the sweet potatoes. The plants were very healthy and we were expecting a bumper crop. One thing I did notice over the summer is that there were lots of ants on the leaves, although the leaves looked pretty healthy. Did the ants eat the potatoes? When we dug up the garden today, we did not see any ants.
We are really disappointed by this and are wondering if we should grow them again next year. Any help would be greatly appreciated.
Thanks.
not so sweet potatoes
Hi, Anna, the first question that comes to mind is, Are you rotating the crop or planting sweets in the same soil/plot year after year? Planting the same thing in the same place year after year leads to reduced harvest over time. The “ant” might be the sweet potato weevil (it looks like an ant) and digs into the tubers (filling crevices with fecal matter—big yuck!) creating bacteria and decay. There are other sweet potato pests, too—banded cucumber beetle (yes, “cucumber”), wireworms, silverleaf whitefly…but they do not look like ants.
So it you want to grow sweets next year, make a new bed and fill it with new soil (we would put it several feet or as far away from the other bed as possible), plant something else in the old bed (see this page for suggestions, based on crop rotation http://www.almanac.com/video/how-rotate-your-vegetable-crops ) and, if you can (given how late it is in season) consider growing a cover crop now in the old/sweets bed (see advice for cover crops here: http://www.almanac.com/content/cover-crops-us)
We hope this helps!
Gardening, raising sweet potatoes
I raise beautiful sweet potatoes, and would love to have some recipts for them.reading further I see the answers ,thanks.
Sweet potatoes
We grew some sweet potatoes for the first time this year. They grew really well and we had three very large single ones but the rest were in a huge tangle wrapped around each other and some very hilarious shapes. Do you know what we did wrong? They still tasted delicious by the way! Best wished , Liz Bean
oddly shaped sweet potatoes
Hmm. Make sure that your soil is loose and fluffy, sandy loam is good. It should not be compacted, heavy clay, or rocky. The rocks or hard soil can make the sweet potatoes grow into odd shapes. There are also some diseases that can affect the growth/shape of sweet potatoes, but it is more likely the soil. Hope this helps!
Sweet Potato vines
This is the 3rd year that I have grown sweet potatoes. In the past, If I plant outside of our fenced garden area, the vines have been eaten by deer, so this year I only grew them inside the fenced area. They were doing great through the end of August. The we had a lack of rain and the leaves were getting eaten to the vine (I believe it is squirrels that can get into the fenced area). By Sept 20 or so, I had a large raised bed of leafless green vines. It's now early October and I usually wait another 3-4 weeks to harvest.
Questions:
1) Any suggestions on avoiding further damage? Is it worth the energy to put netting over the bed - or some other deterrent?
2) Should I go ahead and harvest now? or wait until right before harvest
3) Any recommendations for next year. The squirrels also ate quite a few tomatoes this summer.
sweet potato woes
Goodness! So sorry to hear about your sweet potato troubles. Here are some thoughts.
1) If you think it might be squirrels, you might visit the following page for tips on control: http://www.almanac.com/pest/squirrels
If you think there is a possibility that another animal, such as a rabbit, might be the culprit, here is an article that helps to identify what animal might be causing damage: http://www.almanac.com/blog/gardening-blog/be-critter-detective
http://www.almanac.com/pest/rabbits
2) You might dig up one potato to assess its condition. If it looks like it needs a little more time, then wait for the harvest a little longer. If the vines are still green, it could be that the potatoes are still getting the nutrients they need to grow/mature. If the vine is starting to yellow at the tips, or a frost is expected, then harvest them as they are.
3) Try to identify the exact culprit, whether it is entering the garden from holes underground or from climbing the fence. If from overhead, you might, as the least expensive option, try covering the plants with row covers or plastic tunnels. A determined squirrel may chew through it, but it might deter some. Chipmunks can easily get under those, however. For those the burrow, as well as climb, a more elaborate physical barrier system may be needed to enclose your garden (such as wire overhead fencing to deter climbers, and wire mesh buried in an L-shape pointed outward along the perimeter to deter diggers). Motion-detector sprayers might be another option. Repellents may also help.
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