What you see: Purple sprouts and stalks emerging from your sweet potato.
What it is: A sprouting sweet potato.
Eat or toss: Eat! A sweet potato with a small bunch of sprouts is still safe and will taste fine. Even the sprouts themselves are edible (unlike regular potato sprouts).
Sprouting sweet potatoes are different from sprouting “regular” potatoes
Yumi R. of Washington, D.C. forgot about this sweet potato on an open shelf, discovering two weeks later that it had sprouted a crown of little purple vines.
Like Yumi, you may be concerned about such a sweet potato, especially if you’re aware that when “regular” potatoes (say, Idaho russets) produce sprouts this size, you definitely want to cut them off. Potato sprouts contain toxins that can sicken people.
It’s safe to eat a sprouting sweet potato
But, sweet potatoes, despite their name and appearance, come from an entirely different plant.
So, great news for Yumi and her purple moptop root! Louisiana State University horticulturist David Picha assured me that not only are sweet potato sprouts free from dangerous loads of toxins, they’re also edible.
What to do with a sprouted sweet potato
Eat it! A sweet potato that’s just starting to sprout, like Yumi’s pictured above, is perfectly fine to eat. But don’t wait too long.
Developing sprouts drain nutrients, sugars and water from the roots, ultimately leading to dry, pithy sweet potatoes. They might start to look dehydrated and leathery, sort of collapsed–at that point you won’t want to eat the potato. Older sweet potatoes are also more vulnerable to microbes that cause rot.
You can even eat sweet potato sprouts!
Sprouts like these may not be culinary stars, but chop up the purple bits and they could add crunch to a salad or blend into a stir fry. (And full disclosure: we haven’t sampled them yet ourselves, but reader Graham W. reported that they were “tasty.”) Just make sure the sprout is still tender. They toughen up with time.
Why do sweet potatoes sprout?
Much of it comes down to the local weather. After a couple of weeks at about 70 degrees Fahrenheit, a sweet potato’s biological clock will say, “Hey! It’s time to sprout!” At higher temperatures, that clock ticks faster.
A sweet potato will not sprout if it’s stored between 55 and 57 degrees, a range that would hardly be possible (or worthwhile) for the average home cook to try to replicate. A root cellar might come close. But a fridge is too cold for sweet potatoes and will mess with their flavor and texture—don’t do it!
You’re best off storing your sweet potatoes in a cool, dark, dry, well-ventilated space, according to SaveTheFood. That website estimates their shelf life as one to two weeks in those conditions; here at EatOrToss headquarters, we’ve found that they can last much longer. But, as the temperature warms they’re more likely to sprout.
Eating the fresh sprouts is a fine option. But Picha notes that it’s a small amount of food and the nutritional value of the early shoots won’t be as high as the leaves they might one day develop. Check out the sweet potato below, in all her leafy glory.
How to plant a sprouted sweet potato
If the sweet potato has sprouted so much it’s past edibility, Picha suggests burying the potato horizontally in moist potting soil and leaving it in a container in a sunny, warm (75 to 85 degrees Fahrenheit) spot. In a few weeks you should have some sweet potato vines in the works, as well as some tender leaves ready for harvest.
In certain regions in Africa and Asia, people often eat sweet potato greens. Because they can be harvested repeatedly without disturbing the starchy roots below, the sweet potato plant makes efficient use of the land.
- David Picha. Professor of Horticulture. Louisiana State University. Brandon K. Parker. Extension Agent – Commercial Horticulture. North Carolina Cooperative Extension Service
- Sweet Potato. Vegetable Produce Facts. Post Harvest Center – University of California. Marita Cantwell and Trevor Suslow. Department of Plant Sciences, University of California, Davis Sweet Potato. Home & Garden Information Center. University of Maryland Extension.
- Can you eat sweet potato leaves? Introduce this leafy green into your diet. – by Rhys McKay. 16 DECCan you eat sweet potato leaves? Introduce this leafy green into your diet. – by Rhys McKay. 16 DEC 2019. Better Homes and Gardens.
- Wilmer A. Barrera, David H. Picha. Ascorbic Acid, Thiamin, Riboflavin, and Vitamin B6 Contents Vary between Sweetpotato Tissue Types. HortScience, November 2014
- Nutritional and Medicinal Qualities of Sweetpotato Tops and Leaves. Shahidul Islam Professor Plant Science. Cooperative Extension Program FSA6135 University of Arkansas at Pine Bluff
- Sweet Potato Greens. Sustainable Farming Project. Tufts University.
- Growing Sweet Potatoes in the Sacramento Area. Cooperative Extension-Sacramento County. Environmental Horticulture Notes. University of California Agriculture and Natural Resources. October 2017, updated. May 2017 revised, February 2014, written by UCCE Sacramento County Master Gardener Gail Pothour.
- Mechanism of Hardcore Formation in Chill-Injured Sweet Potato (Ipomoea batatas) roots. R. W. Buescher, M.R. Balmoori. Journal of Food Biochemistry. March 1982
This post was published on May 1, 2020, and updated on Jan. 10, 2024.