How to Grow Sweet Potatoes
Learning to grow sweet potatoes is surprisingly easy—just a few plants provide a plentiful harvest. Sweet potatoes need a long warm growing season, are heat-tolerant and drought-resistant, and have few pests or diseases. This makes them perfect for growing in Arizona’s low desert (yay!). Here are eight tips for planting, growing, and harvesting sweet potatoes.
Article Outline:
- Plant sweet potatoes at the correct time
- Prepare soil correctly before planting sweet potatoes
- Plant sweet potato slips
- Allow vines to grow for larger sweet potatoes
- Water deeply, less often
- When to harvest sweet potatoes
- Harvest sweet potatoes correctly
- Cure and store sweet potatoes correctly for the longest storage life
HOT CLIMATE SWEET POTATO CURING TIP
HOT CLIMATE SWEET POTATO STORAGE TIP
8 Tips for Growing Sweet Potatoes
1. Plant sweet potatoes at the correct time
Plant sweet potatoes 2-3 weeks after the last spring frost, when the soil temperature is at least 65℉.
In the low desert of Arizona:
- Begin making sweet potato slips indoors from January through April.
- Plant sweet potato slips outdoors from March through June.
Sweet potatoes are a great crop for summer planting. Here’s the full list of what to plant in June.
2. Prepare soil correctly before planting sweet potatoes
Sweet potatoes need well-draining slightly-acidic soil. Amend clay soils heavily with compost. Soil should be worked to a depth of at least 8-10 inches. Sweet potatoes can also be grown in raised beds or large containers. Plant in an area with full sun and/or afternoon shade in the low desert.
Find more vegetables that grow well in containers in this guide.
3. Plant sweet potato slips
Sweet potatoes aren’t grown from seed like many other vegetables. Rather, they are started from slips – rooted sweet potato shoots grown from a mature sweet potato. Grow your slips from sweet potatoes or purchase slips.
Looking for more information about how to grow sweet potato slips? This article about how to grow sweet potato slips will help.
Most varieties of sweet potatoes do well in the long growing season of the low desert. In higher elevations or places with shorter growing seasons, choose from quickly-maturing varieties such as ‘Beauregard’ and ‘O’Henry’.
Plant rooted slips deeply, burying slips up to top leaves. Space sweet potato plants 12-18 inches apart. Water well and feed with a starter solution high in phosphorus (if your soil lacks phosphorus) to ensure the plants root well.
4. Allow vines to grow for larger sweet potatoes
Occasional small harvests of greens to eat is fine, but do not prune back vigorous vines for the best-sized harvests. The size of the sweet potatoes is determined by the amount of sunlight the leaves receive. More sunlight and leaf surface area that receives sun means larger sweet potatoes.
If space is an issue, consider growing vines vertically up a trellis to allow sunlight to reach the leaves and produce larger sweet potatoes.
Check longer vines occasionally and lift them up to keep them from rooting in the soil along the vines. Additional rooting will take energy away from the main tubers and instead create many undersized tubers.
In this article, learn more about using cover crops during summer to improve garden soil.
5. Water deeply, less often
Deep watering is crucial for sweet potatoes during hot dry periods. However, it is important to let soil dry out somewhat between waterings. Sweet potatoes tolerate dry conditions better than soggy ones.
6. When to harvest sweet potatoes
Here are a few things to look for before harvesting sweet potatoes:
- The longer a crop is left in the ground, the higher the yield.
- Sweet potatoes may be ready to harvest between 90-120 days after planting.
- Harvest when tubers are at least 3 inches in diameter.
- Harvest sweet potatoes before the first fall frost.
- When the leaves and vines begin turning yellow, production is slowing down. Leave them in the ground a little longer for the largest tubers.
- Once the top growth has died down, remove foliage and harvest.
7. Harvest sweet potatoes correctly
Once you have decided to harvest the sweet potatoes, cut back vines and loosen soil around the plant with a spade fork. Carefully find the primary crown of each plant, and use your hands to dig up the tubers. Shake off any excess dirt, and handle tubers carefully to prevent bruising. Keep harvested sweet potatoes out of direct sunlight. Do not wash sweet potatoes until ready to use for longest storage life.
8. Cure and store sweet potatoes correctly for the longest storage life
To cure sweet potatoes, set potatoes in a single layer (not touching) in a warm (about 80℉) humid area for 10-14 days. Curing allows cuts and bruises to heal and helps the starches inside the sweet potatoes convert to sugars.
HOT CLIMATE SWEET POTATO CURING TIP:
Put the sweet potatoes in a single layer in a plastic grocery sack (cut a couple of holes in the bag for ventilation) to trap moisture in a warm spot INSIDE your house. Outside temperatures may not be the right temperature for sweet potatoes to cure properly.
The curing process is complete if the skin remains intact when the sweet potatoes are rubbed together. Sprouting will occur if potatoes are cured too long. After curing, throw out or immediately use any bruised potatoes.
Use your cured sweet potatoes to make our favorite sweet potato casserole.
Store cured sweet potatoes in a cool (about 55-65℉ if possible) dry area for the longest storage.
HOT CLIMATE SWEET POTATO STORAGE TIP:
If stored above 70°F, the storage life of sweet potatoes is shortened considerably. When outside temperatures are cool, store sweet potatoes in the garage in a box with individual potatoes wrapped in newspaper. Once temperatures heat up, bring the box inside to your coolest room. Check potatoes often and use any right away that show signs of sprouting or rotting.
Thank you very much I didn’t know you could grow sweet potatoes in the AZ. desert. I thought the climate had to be humid.So again thank you.
Can you grow sweet potatoes the way you do regular potatoes in those 40 gallon grow bags?
Potatoes and sweet potatoes grow differently. It may need a larger growing area, but you could give it a try. Use the largest size bag you can and fill it completely before planting the slips, rather than adding soil as the potatoes grow (as you would with regular potatoes).
My neighbor grows the bush variety in grow bags. The bush variety yield has been smaller than the vining variety in her experience.
That’s great to know that you can grow some types in grow bags. Thanks for the feedback.
So when do I start doing the slips process ?? I have to have them ready around may to June to transferred them??
It can take 2-3 months. So count back from the best time to plant for your area.
My first try didn’t work out so well I planted too late. They are tiny more like green beans fat green beans. Can I still eat them?
Sure. They are edible at any stage.
Can you eat the sweet potato you used to make starts when you’re done getting sprouts?
Maybe? Usually it’s pretty shriveled up by the time it’s finished, but it’s probably still edible.
I like the plain and simple honesty of this comment. No one of us can know everything or have answers to everything, and when we don’t have the answer, that means someone should try it and report back and teach the rest of us!
This is precisely the thing that is making me subscribe to your site, even though I live in New England and have a completely different set of growing conditions than you do! We should all always be learning and sharing and helping each other toward success! Good on you!!
Technically you can but scientifically you shouldn’t.
Look up how their composition changes.
Hi Angela! I’m in Gilbert, AZ and temps are supposed to be in the high 70s-low 80s during the day and 50s at night for the next couple of weeks. It’s not very humid, though. Would the back patio be a good place to cure these sweet potatoes right now? I’m not sure where to find a place around 80 degrees and humid without setting up a humidifier in the house but temps are only in the 70s inside, too. Thanks!
I cure my sweet potatoes by putting them in plastic grocery bags near a warm window. The bag traps the moisture and helps them cure.
Great idea! Thank you!
Hi. I have been loving your videos and information you have presented. I’ve successfully grown sweet potatoes but I’m stumped as to how to store them at 55 to 60° in Arizona. The fridge is too cold, the garage varies in temperature too much and my house is at 70°. Where do you store yours? What options do I have for storing at the required temperature for long term? I also want to grow potatoes and some more squash this year which will also need to be stored. Thank you for any help you may offer.
Hi Margaret. It’s true – it can be tough. I added some storage tips to the article. We usually store ours in the garage and use them up before temperatures warm up in the spring. Storage is definitely tricky here in the low desert.
Hi there, I’m in Gilbert, AZ! I do not have anysweet potato slips. Is there any where I can buy slips or speed up the process of making them so I can get something in th ground?
I haven’t seen any for sale. I would try using the soil method of starting slips and look for sweet potatoes at the store that are beginning to sprout – that would speed it up a bit for you.
@Angela Judd,
do you need, or should you use a trellis for sweet potatoe vines?
I usually let mine tumble on the ground. I have seen people use a trellis for them with success.
Good morning, I planted my slips in April, and this morning I found two big potatoes pushing up out of the ground. I wasn’t expecting to harvest until the fall. This is my first time growing sweet potatoes. Should I cover the potatoes with dirt? Leave them alone? Seems to soon to harvest. I wonder if I planted the slips too shallow. Thanks!
I’d cover them up if you don’t want to harvest right now.
I’m in mesa, New to gardening, and I just want to say your blog will help me so much. I feel like you just saves me 5 years of trial and error. Thanks so so so much
You’re so welcome! Best of luck to you.
Live in Lake Havasu City new to gardening in AZ. Had a great garden in high desert in Ca. Can I use the same planting times as the Phoenix area? We are a lot hotter here. Getting shade cloth for my raised beds .
Dates may be similar, not exact. Use our dates as a guide and go from there. Soil temperatures may also be helpful for you to determine planting times.
[Zone 7] I had a purple sweet potato slip, Molokai, given to me in the middle of the summer. I put it in a peat pot, & it is well-rooted, but I never put it in the garden. Should I plant it in a bigger pot & keep it indoors? Put it in the garden now?
Sweet potatoes do not like cold weather, so I wouldn’t plant them outside this fall. If you can keep it alive through the winter and plant it out next spring, that may work.
I planted some slips, and a few sweet potatoes last summer. They took off quite well. Then they were an inch tall. Deer! They always attempted to regrow, and the deer would get around my protections. Aggravated me. This year, I may go full electric fence on the predators. They ate my beets, my carrots, beans, corn and anything else I had out in the garden. I planted some grapes and had those chewed up as well. Even my fruit trees and a bald cypress tree. I haven’t hunted in a while, but if I can’t harvest my veggies, I may harvest a deer or two.
Hi Angela,
Thanks for all your helpful information. When you say sweet potatoes can take full sun, how much exposure can they take here in Phoenix? I have a bed at the inside corner of my block fence, so it’s got hot, reflecting surfaces on two sides. It also gets full sun until about 3 hours before sunset, year-round. Is that going to be too much for sweet potatoes? (I’ll be planting the first week of May.) It’s such an intense amount of sun I’m not sure what will do well in that spot. Thanks again!
First time growing sweet potatoes in the Deer Valley section of North Phoenix. I ordered 10 slips that I expect any day. Does it make sense to successive plant or all at once. If successive planting is the route I go, how do I keep the slips not planted viable. I plan to put one each in 10 gallon potato grow bags.
They are a long season crop – its best to get them all in the ground right away.
Hello,
I’ve removed the slips from the sweet potato and have placed them in water to root.
If it’s warm enough, can I leave the glasses of slips outside? Or is it best to complete the rooting process inside?
Thanks so much for your help!
You can do it outside, I would avoid full sun areas if it’s really hot. Keep an eye on the water level, it could dry out more quickly outside.
Hi.
My sweet potato slips are very large and starting to vine while still in the jars? Is there anything I can do to slow the growth or can I plant in temporary pot until I can plant outside in my garden beds. Help please!
You can cut them in half and make two slips if you want or just trim. You could also plant in a pot while you wait. Good problem to have 🙂
Hi I’ve been growing sweet potato slips. They have gotten very large. Some of them have started to vine while still in the jars with water. Is there a way to slow their growth. Or can I temporarily plant them on pots and transplant in February or March. Please help. Thanks so much.
I’ve been growing sweet potato slips. Some are quite large and are starting to vine while still in the jars of water. Is there anything I can do to slow the growth. Or can they be temporarily put in pots and transplanted outside when it gets warmer. Any suggestions will be greatly appreciated. Thanks.
I’m about to try growing Japanese sweet potatoes (they call this variety ‘imo’, they’re a deep burgundy with cream=colored flesh that is beautifully sweet and when cooked is the texture of a ripe banana.) Has anyone here tried growing these? I picked my potatoes up for growing slips from a local Asian market. I used to eat these in Japan and have cooked the same ones that I bought to grow slips from– they’re truly delicious!