I was out in my garden early this morning checking on my sweet potatoes and let me tell you—this heat wave we’ve been having hasn’t slowed them down one bit. While some plants like my tomatoes have been struggling, sweet potatoes thrive in the heat. They’ve been spreading like crazy, and I’m starting to wonder if it’s time to dig them up. If you’re growing sweet potatoes too, you might be asking the same question: How do I know when they’re ready to harvest?
Signs Your Sweet Potatoes Are Ready
Sweet potatoes are typically ready to harvest about 90 to 120 days after planting, depending on the variety. I planted mine around the end of May so I should have a harvest by the end of August, mid-September. But here are a few key signs to look for:
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The leaves start to yellow and die back. This is your plant’s way of saying, “Hey, I’m done growing!” Mine are still green and growing!
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You know your frost date is approaching. Sweet potatoes are sensitive to cold, so you want to dig them up before your first frost. Cold soil can damage the roots. My first frost is mid-October so I have plenty of time.
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You just can’t wait any longer. If it’s been at least 90 days, you can do a test dig on the edge of the bed. Gently pull back the soil and peek at the size of a few roots. If they look plump and usable, you’re good to go.
They May Not Look Like Store-Bought—and That’s Okay
Homegrown sweet potatoes often look a little funky. They might be shorter, rounder, or even twisty compared to the perfectly shaped ones at the store. But don’t worry—there’s nothing wrong with them! In fact, some of the oddest-looking ones have the best flavor.
Uneven watering, compacted soil, or damage during harvesting can cause them to take on unique shapes. But once they’re cooked up, they’ll taste just as sweet and delicious.
How to Harvest Sweet Potatoes
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Cut back the vines a few days before you plan to harvest. This signals the plant it is time to toughen up their skins.
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Use a garden fork or shovel to loosen the soil around the plants—start about 12-18 inches away from the center so you don’t nick the roots.
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Gently lift the roots out of the ground. Sweet potatoes bruise easily, so handle them like eggs.
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Brush off the dirt, but don’t wash them yet.
Curing and Storing for Long-Term Use
To bring out their sweetness and make them last in storage, you’ll need to cure your sweet potatoes.
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Place them in a warm, humid spot (around 80-85°F with 85-90% humidity) for about 7–10 days.
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A covered porch, warm shed, or a storage tote with a loose lid in a warm room can work well. Just check for airflow and avoid stacking them tightly.
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After curing, move them to a cool, dark place (55–60°F) for storage. They can last for several months if kept dry and away from light.
Avoid refrigerating raw sweet potatoes—it can mess with their texture and flavor.
The summer garden may be winding down, but the fall season is just getting started!
Join me for a live Fall Garden Planning Class on August 5 at 2pm (ET)—it’s just $9 and perfect for gardeners who want to keep the harvest going. I’ll walk you through what to plant, when to plant it, and how to make the most of your garden space this fall.
👉 Click here to save your spot!
Let’s keep those garden beds productive—even after the heat fades.
Happy Gardening
Karen