The process for harvesting, curing, and storing sweet potatoes is simple once you get the hang of it, but there are a number of steps to know about. Here’s your step-by-step guide to having delicious, homegrown sweet potatoes in time for Thanksgiving Dinner.
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Growing Sweet Potatoes
Sweet potatoes are almost a set-it-and-forget-it crop, which is why they made my short list of low-maintenance crops!
Plant sweet potato slips late in spring after the danger of frost has passed, and harvest in the early fall.
This crop likes it sunny and hot, so watering is only essential for keeping the soil from being bone-dry. In other words, this crop is great for a water-wise garden.
They’re generally pest-free, too.
If you haven’t picked up on it yet, sweet potatoes are one of my all-time favorite crops!
I like to grow the variety ‘Georgia Jet’, which is a sweet, orange variety known to be high-yielding and accommodating of a variety of climates and soil types.
Sweet potato vines also produce well when trellised to grow vertically because they develop several big tubers at each root junction. In the more traditional garden approach, vines sprawl along the ground, producing a bunch of tiny potatoes as they try to root everywhere.
How to Harvest Sweet Potatoes
Harvest any time after tubers have started to form; start checking late summer. I like to wait at least until the leaves start to yellow, which indicates that I’ve gotten the most production I can out of the vines that I’ve planted.
The key to a superior, sweet taste, however, is allowing them to experience a light frost, and then harvesting before a hard frost. So you may want to let them stay in the ground a little while longer and keep an eye on the weather.
Here’s the two-step process I use when harvesting my sweet potatoes.
Step 1 for Harvesting
Choose a day when it hasn’t rained for a few days, that way the soil is minimally moist and crumbly, and you can brush off the tubers with a very light touch.
You don’t want mud caked onto the tubers because it makes them harder to clean and store.
The harvesting process starts with cutting the vines back so you can get to the soil. Growing sweet potatoes on a trellis makes it easier to follow the vines and find the location of the tubers.
Cut off the vines, leaving six-inch lengths above ground as a sweet potato beacon.
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Step 2 for Harvesting
This step is a delicate one. At this stage, the skins of the tubers are very thin and easily damaged. Carefully and slowly push away the soil to reveal the harvest treat.
Then loosen the soil around the tuber, digging under it to lift it out gently. I like to use my hori hori garden knife for this step.
Interested in a garden knife? I still have the one my gardening mentor bought me–my own special left-handed one. It still looks like new today, more than ten years later! (And here’s a great garden knife for right-handers.)
Whether you’re using a hori hori knife, a digging fork, or a shovel for harvesting, don’t aimlessly stab into the soil, as you’ll risk cutting the tubers in half. Once you’ve found one, don’t pull it out, because the delicate gems will undoubtedly snap in half, leaving the other half buried.
Pieces of tubers won’t store as well as whole, unscathed potatoes.
So dig gently, find a tuber, loosen, and lift. Having loose soil really helps, so consider growing yours in a raised bed.
You’ve harvested your tubers and now you’re probably thinking that you’ll head straight to the kitchen to make a sweet potato casserole, right? Wrong. 🙁
It’s hard to wait, but the curing process really sweetens them up.
How to Cure Sweet Potatoes
Curing is a necessary step that sweetens the flavor and allows the skins to harden for optimal storage. Be patient and don’t rush the process!
The first step for curing sweet potatoes lasts about 10 days, and the second step lasts about six weeks.
Step 1 for Curing
This first step for curing sweet potatoes heals any damage that occurred to the tubers during harvest so they store longer. It also kicks off sugar production to give you sweeter tubers.
For this step, the ideal scenario is an 85-degree room with 85% humidity. What? You don’t have that?!
My solution for years now is this: Punch a few holes in plastic grocery bags and fill them with a single layer of tubers in each bag. Tie the bags closed and put them in your sunniest, warmest window. This creates a sort of greenhouse effect.
Leave for 10 days.
If it gets chilly and your windows are drafty, put a blanket or towel over them to keep them warm.
After 10 days, open your plastic bags of curing tubers. They should be moist and much harder to the touch. Compost any soft ones.
While you can technically cook your sweet potatoes now, continuing with this next step kicks off even more sugar production and prepares them to store even longer.
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Step 2 for Curing
Curing for up to 6 more weeks makes the sweetest sweet potatoes.
Roll up each tuber separately in a single sheet of newspaper, stacking them in a cardboard or wooden box, or any breathable storage container. Place it in a basement or other room where the temperature is close to 55-60° F, for six weeks.
This six-week period develops the hard skin necessary for long term storage, and kicks off even more sugar production. The newspaper allows aeration and prevents moisture build-up that could otherwise ruin the harvest.
When can I cook homegrown sweet potatoes?
Follow my curing method described above for at least 10 days, and an additional 6 weeks after that, in order to cook tubers at the peak of sweetness.
So if you want to serve sweet potato casserole at your Thanksgiving Dinner, harvest in early October at the latest. You may not get that frost-kissed sweetness, but the curing process sweetens them up.
How to Store Sweet Potatoes
After curing, you can store them for 6-8 months in ideal conditions:
- Breathable container or mesh bag
- Cool temperature, around 55° F
- Around 60% humidity
Actual storage length depends on post-harvest conditions. The process for harvesting, curing, and storing sweet potatoes sounds complicated and time-consuming, but really it’s simple once you get the hang of it.
The taste of these homegrown, sweet orange gems that say ‘Thanksgiving’ is all you need to convince yourself to grow them year after year!
5 FAQs about Harvesting, Curing, and Storing Sweet Potatoes
#1: When do you plant sweet potatoes?
Plant sweet potato slips in a sunny spot late in spring after all danger of frost has passed.
#2: When do you harvest sweet potatoes?
Sweet potatoes can be harvested any time tubers have formed, starting in late summer. However, allowing them to experience a light frost and then harvesting before a hard frost is the key to a superior, sweet taste. Harvest in early October if you’d like to sweeten them through curing in time for Thanksgiving.
#3: How do you preserve sweet potatoes after harvesting?
Sweet potatoes can be preserved through canning, dehydrating, or freezing.
They also store a long time in a cool, dry pantry, similar to regular potatoes, when first prepared through a curing process.
#4: Do you need to cure sweet potatoes before eating them?
While you can eat them immediately after harvest, they are sweeter after being cured.
#5: How long can you store sweet potatoes?
You can store cured sweet potatoes for 6-8 months in ideal conditions.
Are sweet potatoes one of your favorite crops? What is your method for harvesting, curing, and storing?
We’re harvesting ours this weekend. Got them in a bit late. Instead of trellising, we just cut ours back if they grow out of control. You can also eat the leaves. I put them in smoothies a few times, mild and tasty.
There is a sweet potato weevil, so be on the lookout for that. Our harvest last year ended up ruined, or what was left of our harvest, in the late spring when I pulled them out to eat and found the bugs had eaten holes all over the potatoes.
cool, never thought to eat the leaves. Good luck with your harvest!
What kind of sweet potatoes do you grow Amy?
Amy Stross says
I like to grow the Georgia Jet variety. It’s known for being highly productive in cold-prone regions (like mine), it stores well, and it has beautiful orange flesh. It is also earlier to mature than other varieties in case we have an early winter. I’m in hardiness zone 6.
Thanks, We shall give them a try.
Angi @ SchneiderPeeps says
We harvested our sweet potatoes a few weeks ago. I planted a few vines in a big pot and brought it into our bathroom to overwinter. It’s an experiment, we’ll see how it goes. I hadn’t thought of trellising them, I might try that next year.
Great idea to grow your own slips. I’ve grown a few on a kitchen window, but it wasn’t enough to plant a whole bed 🙂
Just wanted you to know I stole your idea to cure in a plastic bag – I must say it’s genius!
To be nerdly, I put a temperature and humidity sensor in the bag and it stays a VERY steady 85% humidity. I’ve seen it dip only as low as 84% and only as high as 86%. The temp stays just above room temperature…which for my bag is about 73º-74ºF. We’ll see how they turn out in another week or two!
(I may try putting the whole bag – sealed up a little more – in my dehydrator at its lowest setting, which is 85º-90º….but for now that’s just an idea.)
I’m so glad the plastic bag curing method passed the nerd test, LOL!
lisa M says
Thanks for linking up with Green Thumb Thursday last week! I really love this article….I’ve chosen to feature it this week. Stop by and pick up a featured button for your blog.
Thanks for linking up! I’d love it if you’ll link up again this week!
I planted my sweets in late April, and this is my first time growing them. I bought slips from Home Depot, if that matters? I put them in tall wicker baskets (bunched together) full of compost and soil, with a trellis for the vines to grow up. I did this because I heard the tubers will bust through the bottom of the basket when they’re ready to go into the ground, and by that time, the ground would be nice and warm for them, plus they look so pretty. A couple of the baskets I used were not as tall ( about 6-8″ tall) and I’ve noticed that a couple of my sweet potatoes are above ground, and a very nice size (about 6″ long and 3.5″ wide). Does that mean they’re ready to be dug up, or should I still wait a little while? I live in Northern KY, I think it’s zone 4 or 6, I have to double check, but the weather is still in the 80-90’s, and I don’t see a light frost until mid October. Am I still doing everything ok, or should I start digging them up and putting them in bags now? I’m really hoping to use my own homegrown sweets this Thanksgiving. Thank you, I love the article!
You can harvest them anytime now, but a light frost will improve their sweetness. I might wait a bit longer and harvest them early- to mid-October to allow time for them to be cured for Thanksgiving (and possibly receive a light frost). Congrats on your harvest 🙂
Is the soil knife you’ve linked to on Amazon the left-handed on that you love so much?
I’ve looked high and low for the left-handed knife. I would recommend contacting the supplier that made mine, A.M. Leonard. They don’t advertise it in their catalog, but a friend of mine who is a professional horticulturalist has one, and she and her team also got theirs from A.M. Leonard. Perhaps it needs to be special-ordered?
I had three 5-gal buckets, but was afraid of overcrowding so I only planted 2 plants per bucket. I got a beautiful, but disappointing 7lbs of potatoes, but it was an experiment.
Our cold snap doesn’t leave me with an 85 degree option, so I busted out the solar oven, set it by the window, and am venting as needed to maintain the temp.
Still considering the 55-65 degree option, because in SC it will probably be in the humid 80’s I need now for the next 6 weeks…
It will probably involve a ventilated cooler and ice packs, but if anyone has any ideas let me know. I am in an apartment, no basement etc.
What a great idea to use the solar oven to cure your sweet potatoes! As far as the cooler temps for storing, that may be a challenge. You might find the coolest room in your home and store them in a dark closet. They may not last as long as they would in ideal conditions, but they should last several months at least. Good luck 🙂
I am a total newby to sweet potatoes… How do you prepare for the following year? Do you just save a few cured sweets to plant in the spring? Do you plant the whole potato? Or cut it up? Or break off the shoots? Thanks!
Here is a good explanation of how to sprout your own sweet potato slips.
Last season I grew my first sweet potatoes. I planted some from slips that I had from sweets that a friend gave me from the previous season. I also planted some slips that I bought. This season I planted slips in a what was the circle from a 10 foot across compost pile. I criss crossed chicken wire on the bottom of the old pile and then added enough aged compost to fill the circle to 8 inches. The chicken wire makes it much harder for the moles and voles to get into the bed. A few sweets had some nibbles, nothing like last season. I planted my slips in late April. I harvested most of my sweets yesterday. I will get 60lbs or more. Last season I cured my sweets by letting them sit on a table that gets 3-4 hours of sun. I let them sit outside for 10 days. I did not do anything special to them. They cured very well in temps of the 70’s and lows in the 50’s. I still have some sweets from last season and they are firm, a couple have shoots growing on them. They are sitting in an open box in the dining room.
I made the mistake of potting my slips into 8″ pots while they were still growing indoors. The plants were large and hearty but the roots were constricted by the pots. After transplant they did not spread out in the soil and many of my potatoes grew in tight swirls that made for lots of small potatoes. I think that’s called “outsmarting yourself”. I was too disappointed to take pictures. I will definitely start my slips later next Spring and transplant them directly from the water pot into the soil.
How small is too small to save and cure for a sweet potato?
Technically you would want to cure them all first to have the sweetest taste, but I’ve found that the smallest ones (smaller than the width of a finger) didn’t make it through the curing process. Better to eat those right away. Any others that you consider small will probably make it through curing, but will probably not store as long as big ones, so I would eat them sooner rather than later. Also keep in mind that different varieties tend to be different shapes and sizes, so don’t necessarily compare them to the gigantic ones that you see in the grocery store. 🙂
Geoff Kachel says
I’ve grown a crop of sweet potatoes which produced quite well. I was curious as to whether the potatoes depleted any minerals present in the soil whilst growing, anything that I may need to add before growing any subsequent vegetables in the same part of the garden bed. I understand it all depends on the pre-existing levels prior to the sweet potatoes, I was wondering if there was a rule of thumb to add a particular element to the soil prior to using that part of the garden again.
It’s always a good idea to amend soil after harvesting any crop, since the crop will pull nutrition out of the soil and into the healthy, homegrown produce. I like to amend soil with worm castings and compost after harvesting and before growing sweet potatoes.
Sweet potatoes in particular like a little extra postassium. You’ll find info on different sources of potassium in my free soil guide. Sign up to get it here —->>> Tenth Acre Farm Weekly Newsletter.
You’ll also find lots more details about natural sources of potassium in my book, The Suburban Micro-Farm.
I tried planting a couple of unused store bought sweet potatoes in 2016 and had no idea when to plant or anything about growing them. They sprouted and grew well and I let them ramble around to help much that area of the garden. I did look up when to harvest later in the summer. I waited and harvested them just in time- right before a hard frost. There were many skinny and small potatoes, but I thought they were more usable sizes than the giant ones at the store anyway. I don’t think I cured them the proper way, and I dumped them all in an old bucket and kept them in my basement. After using all the decent ones, I forgot about them and last year, 2017 I decided not to plant them and brought the bucket up to dump in the compost. It was a busy time so I set the bucket out the back door for a few days before taking to the compost. Some of them started sprouting! So I brought them back in the basement and I will try planting them this year. We shall see what happens with my experiment!
I love experiments and serendipitous moments like this one. 🙂
Kathleen Smith says
Thank you! You have do-able explanations. I really enjoy your blog. So practical, and fun!
This may have been mentioned, but sweet potatoes CAN be eaten without curing.
We always dug them, let them dry on the basement floor on paper for a week, then stored them in buckets in the back corner of the basement. They keep for over a year, and sprout willingly for next year’s crop.
Sprouting sweet potatoes can also be eaten.
Absolutely! With curing they will be sweeter with store longer, but it is not required. It sounds like you have good storage conditions that allowed your crop to store well. Curing can benefit those who don’t have perfect storage conditions.
This is such great information! I am growing my first crop of sweet potatoes (by corp i mean six slips planted 🙂 ). I started the slips from scratch in Jan 2019 and planted them the last weekend in April 2019, after the last frost. I am in zone 7a/b. I’ve read to harvest them in 100 days, that would be August 5, 2019. We are still well into the heat of the summer in August in Virginia. I’ve read here to wait until after the first frost which will be late October. Is it OK to keep the sweet pots underground until then?? Should I have planted later?
I am also experimenting. I planted six self-grown slips, grown from half a sweet potato, pinched, then sprouted in water. The experiment is that I had two halves with the shoots just starting so I just planted the entire potato. I don’t know what will be come of this, but we shall see. I appreciate all comments. Thanks!
OH also I planted in a raised bed and i added about six bags of organic soil to the bed to create depth.
Yes, I would leave most of them in until after the first light frost. You can pull a few beforehand if you like, but until they’re cured, they won’t be as sweet.
I just harvested my first sweet potatoes and noticed that several of the tubers had turned to mush. I still got a good amount of tubers that were fine. I have looked and can’t find any sites that could explain what could have been the cause. I planted the slips in a bucket that had good drainage. I look forward to planting them next year and want to avoid any problems next year when I increase the amount I do.
The most common reason for mushy sweet potatoes is a hard frost. I like to wait until after a light frost, but if the temperature gets too cold it can be detrimental. I would say to try harvesting sooner next time.
Hi Amy! We just picked our first ever sweet potatoes today and are so excited!
But I have a question: If we follow your method with curing for 10 days then sitting for 6 weeks, we won’t be able to use them by Thanksgiving. Since ours are already quite firm when we picked them, would we need the curing process?
Yes, I would still cure and store them as I’ve suggested until Thanksgiving. This will ensure that you have the sweetest sweet potatoes potatoes possible to serve at your holiday.
George-Joann Denny says
We have planted sweet potato before but the vines got in wayif harvesting and we finally cut off the vines. Thank u for the info about the vines it would have helped us enormously if we had this info before now. We appreciate all the help. I think we will use trellis next year or cut off the long vines. My husband and I are 80 years old and still live gardening as much as our body allows . Again thank you September 2020
Suzanne Manchester says
George-Joann Denny It’s inspiring to hear you are still gardening at 80 years old! I hope I am still able at your age! I hope you had a great harvest, or will try again next year. I also found out on another website that the vines should not be allowed to root down into the ground, where they will try to start another plant, as that detracts from the primary plant base growing their roots to full size. Our season in NY is too short for that to result in multiple crops. I also read that the vines can be trimmed back if they get longer than 4 feet. I ended up just twisting mine around back on top of the main plant, rather than trimming them. I made a long high hill for my planting, with a flat top and then I planted my slips in that. I took 3′ wide black plastic and laid and pinned it with rocks on the sides of the hill so that the weeds would not grow in the mound. I have had rats devour my crop previously under plastic (too good a shelter to let cats catch them) so after a good canopy of greens was established, I pulled the plastic out from under off the sides of the mound. I did not put irrigation tape or hose underneath and later got very worried because it was so dry in the mound, even though I regularly watered in the trench at the top at the base of the plants. I started applying a lot more water and we finally got some rain too. I have just dug up my roots from two plantsand have 5# 5 oz on Georgia Jet and a little less on Centennial. They are huge. I have ceased watering manually now. I did eat one last week and it was bland and dull, so I am glad to read that curing the sweet potatoes allows the starches to convert into sugars. Thank you Amy for this helpful post!
Do the sweet potatoes get green if they cure in the sun? Or do I cover the plastic bags with a light material sheet?
I’m not aware of sweet potatoes turning green while curing either in the sun or in bags.
Thanks for your informative post! This is my second year with sweet potatoes. Last night in zone 5 an unexpected light frost killed maybe 25% of the leaves. But 10 day forecast is sunny with high temps in 70’s and lows around 50. The slips went in June 15 so it’s only been 80 days. Do the tubers grow significantly in these final cooler days even after light frost? If so, I’ll leave them to fully mature. If not, I’d rather harvest as I do have kale transplants waiting for this area. Opinions?
Growth certainly slows down with cooler temps, but with your forecast they should continue growing for some time. You could harvest them now or allow them to grow until nighttime temps are consistently in the 30s and 40s.
We just harvested our very first sweet potatoes. We were a little disappointed that some of the large ones have split open down the length of the potatoes . Did we wait too long to harvest them? Some of them were HUGE, while others were on the small side. We used a trellis, but only half of the vines took to it. I guess we should have “encouraged” them a bit more.
How much do you clean the potatoes? Do you brush most of the dirt off or leave it for the curing process?
I really appreciate the help here. When we planted our plants, we had no idea of this process. Hopefully, we will have our sweet potato casserole with our crop. Jane
Big rains toward the end of the season can cause splitting, so it’s a good idea to harvest them if you have a long stretch of rain coming, or wait as long as possible afterward for them to dry out before harvesting.
They won’t naturally climb a trellis, you have to manually train them to do so by weaving the vines as they grow.
If you harvest from dry soil, there shouldn’t be much cleaning to do. To help them store longer, don’t clean them until you’re ready to eat.
You’ll have a better harvest next year! 🙂
Don C Birkholz says
The best tasting sweet potatoes I have ever grown were cured in the sun (not on real hot days, more like 70 degrees). When baking, they filled the kitchen with a delicious aroma. I have never gotten that delicious taste since. Last year, I tried heat lamps and burned them all up. I assume the sweet potatoes in the store are not cured properly since they are not sweet unless cooked with brown sugar.
This was my first year of planting sweet potatoes. They have done very well. I planted them in early May and just harvested some this past weekend. I still have some that I have left in the ground. We have not had a cold snap yet. Your instructions on how to cure them were great. I decided to put them into a large plastic tub, cover it with plastic wrap (as I have no lid for that container) and I misted them with a little bit of water to add some moisture for the humidity and placed them in my car for the greenhouse effect. It appears to be working. They are warm and there is good humidity in the tub as proof from the condensation on the top of the plastic. At night, I cover them with a blanket as the nights have gotten cooler. Still no frost. I love sweet potatoes and can’t wait to taste them. They were huge, by the way. It was so fun to harvest them. Almost like a treasure hunt! Thank you for your help!
Glad to hear about your adventures! I hope your cured sweet potatoes turned out tasty! 🙂
Venessa Brown says
Hi. Thanks for sharing these tips. It is always fun for me to learn more about gardening. It has been a year but I still consider myself as a novice. I developed an interest for gardening when I saw my neighbor’s glass greenhouse. IT WAS SO BEAUTIFULLLLL! I got to know that they bought it from Mulberry Greenhouses and bought myself a polycarbonate greenhouse for sale.
I too am a novice at growing sweet potatoes but I did for the 1st time this year and have already harvested them. Question – if you leave a small potato in the ground will it continue to grow even if it’s not connected to the others? I’m very happy with what I have dug up and can’t wait to plant more next year.
My understanding is that a piece of the tuber will not survive if it isn’t connected to the foliage.
John S. says
Any! Great site!
Question: after curing and washing my sweet potatoes, should I remove any straggling roots, 1/8-1/4″ holes and cuts with a knife before storing?
Small harvest, about 15 med to large potatoes, several to be eaten within next week(s) and storing a few to be eaten over the next few months.
Thank you! john
I would not wash or cut any part of the tuber before storage. Any tubers with imperfections such as holes or cuts should be used first, as they will not store as long. Otherwise, you can trim off unwanted parts before preparing to eat.
Maggie Priddy says
I bought a bushel of sweet potatoes that had not been cured. I have had them for 2 weeks and their Skins are very thin. Is it too late to cure them now? If I can cure them now how do I go about it since I’ve already had them for 2 weeks?
I would follow the instructions in this article regardless of when they were harvested. As long as you’re within a couple of months of harvest they should be fine. They may not store as long, but they’ll still be delicious.
cynthia long says
I am curing mine in the oven with a light bulb on a timer and pans of water. The temp has been consistently around 80, but this second batch may have been at too high humidity. Many of the potatoes have sprouted a lot during the 12 day curing process. What should I do with the sprouted ones? Most of the sprouts are on the necks, but some have sprouts in the middle of the potato. Should I try to remove the sprouts? Leave them alone? Will the sprouts affect storage? Will the sprouts affect the next stage of cool curing?
If I were curing them in the oven like this, I would be inclined to crack the door so that excess humidity could escape. It sounds very cozy in there, the perfect environment for sprouting! The sprouted ones are probably not going to store as long, so I would eat those first. Just remove the sprouts, which are edible, before the second phase of curing and storing.