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The best time to pick sweet potatoes is in the late summer to early fall, typically around 90 to 120 days after planting, once the leaves start to yellow and die back.
But knowing exactly when to pick sweet potatoes isn’t just about counting days on a calendar, it’s about reading the signs your plants are giving you and understanding the ideal conditions for harvesting.
If you’ve been wondering when to pick sweet potatoes to get the sweetest, most flavorful roots possible, you’re in the right place.
In this post, we’ll cover how to tell when to pick sweet potatoes based on plant signals, soil temperature, and even the size of the tubers beneath the soil.
We’ll also walk you through the steps to properly harvest and cure them so you can enjoy a perfect batch from your garden.
Let’s dig in and figure out the perfect timing for when to pick sweet potatoes.
When to Pick Sweet Potatoes: Key Signs of Readiness
Knowing when to pick sweet potatoes starts with observing your plants closely, as several clear indicators will point to the right time.
The most reliable sign is the state of the foliage, and once you know what to look for, you’ll never second-guess when to pick sweet potatoes again.
1. Watch for Yellowing Leaves
As the growing season winds down, the leaves of your sweet potato plant will naturally begin to yellow and droop.
This process is a clear signal that the plant has shifted its energy from growing new foliage to maturing the roots underground.
When you see this happening, it’s a solid hint that the time to pick sweet potatoes is approaching, usually within two to three weeks.
So when you notice the lower leaves turning yellow and starting to wither, start preparing for harvest.
2. Check for Vine Die-Back
Another reliable clue for when to pick sweet potatoes is when the vines themselves begin to die back and turn brown.
This isn’t a sign of disease, it’s just the plant naturally finishing its life cycle.
While you might be tempted to harvest as soon as you see this, it’s actually better to wait a little while.
Leaving the mature roots in the ground for a few extra weeks after vine die-back allows them to develop a thicker skin and a higher sugar content.
That being said, don’t wait too long, as frost can damage the roots and ruin your entire crop once you’ve decided it’s time to pick sweet potatoes.
3. Track Your Days to Maturity
For a more precise measurement of when to pick sweet potatoes, you should look at the specific variety you planted.
Most sweet potato varieties are ready to harvest between 90 and 120 days after you put the slips in the ground.
Early-maturing types might be ready right around the 90-day mark, while others need the full 120 days or even more.
Check your seed packet or plant tag for the expected maturity date and use that as a baseline.
Combining this timeline with the visual cues above is the most accurate way to nail down when to pick sweet potatoes in your garden.
4. Consider Soil Temperature
Soil temperature plays a huge role in determining when to pick sweet potatoes, and it’s something many gardeners overlook.
Sweet potatoes thrive in warm soil, and they only continue to grow as long as the ground temperature stays above 65°F (18°C).
Once the soil cools down in autumn, their growth slows dramatically.
So the ideal time to pick sweet potatoes is just before the soil temperature drops below that point, usually in the early fall.
You can use a soil thermometer to monitor this, and once the ground begins to cool, you know the harvest window is open.
5. Probe the Soil for Size
If you’re still unsure about when to pick sweet potatoes, you can do a little detective work by gently probing the soil around the base of the plants.
Use your fingers or a small hand trowel to feel for the tubers and check their size.
While you want to be careful not to damage them, confirming that they have reached a decent size, usually at least a couple of inches in diameter, is a good sign.
Just remember that if they are too small and it’s still early in the season, you can always cover them back up and wait a bit longer to know when to pick sweet potatoes for a bigger yield.
The Best Time of Day to Harvest
Once you’ve figured out the right timing, choosing the right time of day is also crucial for getting the best results.
Plan to pick sweet potatoes on a dry day when the soil isn’t too wet or muddy.
Harvesting in the morning, after the dew has dried, is often recommended because the roots are turgid and full of moisture.
Avoid digging them up in the heat of the afternoon on a very hot and sunny day, as they can wilt and bruise more easily.
Being gentle during the harvest process is key to keeping them intact since any cuts or scrapes will invite rot during storage.
How to Properly Harvest Sweet Potatoes
So you’ve identified when to pick sweet potatoes, and now you need to know exactly how to get them out of the ground.
First, cut back the vines with a pair of garden shears, leaving about a foot of the stem to use as a handle.
Then, carefully dig around the plants using a garden fork, starting about a foot away from the base to avoid spearing the roots.
Lift the soil gently and pull the sweet potatoes out by hand, being careful not to scrape them.
It’s okay to leave them to dry on the ground for an hour or two, but don’t leave them out in the hot sun for too long.
Once you know when to pick sweet potatoes and you’ve actually done it, you’ll move on to the next crucial step.
Curing and Storing for Sweet Flavor
The work isn’t done once you know when to pick sweet potatoes, since curing is essential for that delicious sweetness and long shelf life.
Curing is the process of healing any wounds and converting starches into sugars, which is what makes sweet potatoes taste so good.
To cure them, place the freshly harvested sweet potatoes in a warm, humid area with temperatures around 85°F (29°C) and high humidity for about 10 to 14 days.
After curing, you can store them in a cooler spot, around 55 to 60°F (13–15°C), where they will keep for several months.
Remembering to cure them properly is just as important as knowing exactly when to pick sweet potatoes, as skipping this step can lead to bland-tasting roots.
So, When is the Right Time to Pick Sweet Potatoes?
Now you know that the right time to pick sweet potatoes is in the fall, roughly 90 to 120 days after planting, when the leaves yellow and the vines start to die.
The right time to pick sweet potatoes is also just before the first frost, so you want to keep a watchful eye on your local weather forecast.
Growing your own sweet potatoes is incredibly rewarding, and getting the harvest timing right is the secret to a successful crop.
Hope this guide helps you feel confident about when to pick sweet potatoes from your garden and enjoy the sweet, earthy rewards of your labor.