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You know sweet potatoes are ready to pick when their leaves start to yellow and the vines begin to wither.
Knowing when to pick sweet potatoes is one of the most important steps for getting that sweet, rich flavor you’re after.
If you’ve been wondering how to know when sweet potatoes are ready to pick, you’re in the right place because timing makes all the difference between a starchy dud and a delicious harvest.
So let’s talk about the exact signs that tell you when sweet potatoes are ready to pick, plus how to dig them up without damaging those precious roots.
We’ll also cover what happens if you pick them too early or too late, because that’s a common mistake that can really affect your crop.
By the end of this post, you’ll have total confidence in knowing when sweet potatoes are ready to pick from your garden.
Let’s dive right in and get those sweet potatoes out of the ground at just the right moment.
Key Signs That Tell You When Sweet Potatoes Are Ready To Pick
The most reliable way to know when sweet potatoes are ready to pick is to watch the plant itself, because the foliage gives you clear signals.
While you might be tempted to dig early out of excitement, patience really pays off with these underground treasures.
Here are the main indicators to look for so you can pick sweet potatoes at peak maturity.
1. Count the Days from Planting
One of the simplest ways to know when sweet potatoes are ready to pick is to mark your calendar on planting day.
Most sweet potato varieties need about 90 to 120 days to mature fully.
If you planted slips in late spring, that usually means your sweet potatoes are ready to pick sometime in early to mid-fall.
Check the specific variety you planted because some types mature faster while others need the full 120 days.
So if you’re nearing that 90-day mark, start paying close attention to the other signs below.
2. Watch for Yellowing Leaves
When sweet potatoes are ready to pick, the lower leaves of the plant will begin to turn yellow.
This yellowing is a natural signal that the plant is shifting its energy from growing leaves to ripening the roots underground.
You’ll notice the older leaves fading first, and then the yellowing will spread upward as harvest time approaches.
If you see this happening around the 90-day mark, your sweet potatoes are likely getting close to being ready to pick.
Just remember that some yellowing can also happen from stress or drought, so combine this sign with the others before you dig.
3. Check the Vines for Withering
Another solid clue that sweet potatoes are ready to pick is when the vines start to wither and die back.
The lush green vines that sprawled across your garden will begin to look tired, droopy, and even brown at the tips.
This die-back is completely normal and it’s actually the plant telling you that the sweet potatoes have finished developing.
When you see significant vine die-back, you can usually start picking sweet potatoes within a week or two.
Don’t wait too long after this stage because the roots can become overly fibrous if left in the ground too long.
4. Dig a Test Sweet Potato
If you’re still unsure about when sweet potatoes are ready to pick, the best way to check is to gently dig up one test root.
Carefully loosen the soil near the base of the vine with your hands or a small fork, then feel around for a decent-sized sweet potato.
A mature sweet potato is ready to pick when it’s at least two inches in diameter, roughly the size of a large egg.
If the skin is thin and easily scratches off with your fingernail, they’re not quite ready yet.
If the skin feels thicker and doesn’t scrape off easily, then your sweet potatoes are ready to pick.
This test takes just a minute and gives you a direct answer about your crop’s readiness.
How Weather Affects When Sweet Potatoes Are Ready To Pick
Your local climate plays a huge role in determining when sweet potatoes are ready to pick, so you can’t just rely on a fixed date.
Sweet potatoes are warm-season crops that love heat, so they need plenty of hot days to develop properly.
If you had a cooler than usual summer, your sweet potatoes might need extra time to mature.
Conversely, a hot, sunny summer can speed up their growth and make them ready to pick earlier than expected.
Here’s what you need to keep in mind about temperature and harvest timing.
1. Soil Temperature Matters
Sweet potatoes grow best when the soil temperature stays between 70°F and 85°F.
If soil temperatures drop below 55°F, the roots stop growing completely.
That’s why you should always aim to pick sweet potatoes before the first frost of autumn.
Even a light frost can damage the roots near the surface, making them rot quickly in storage.
So if a frost is predicted and your sweet potatoes seem close to maturity, it’s better to pick them a little early than to lose them.
2. Rain and Moisture Levels
Right before you plan to pick sweet potatoes, avoid watering the area for a few days.
Moist soil makes it messier to dig and can bruise the tender skin of the sweet potatoes.
Dry soil is much easier to work with, and it helps the roots clean up nicely.
If heavy rain is in the forecast, wait until the soil dries out a bit before harvesting to prevent damage.
Dry conditions also help your sweet potatoes start the curing process correctly after you pick them.
How To Pick Sweet Potatoes Without Damaging Them
Once you’re certain sweet potatoes are ready to pick, it’s crucial to dig them up properly to avoid cuts and bruises.
Unlike regular potatoes, sweet potatoes have very thin skin that bruises easily when handled roughly.
Always use a garden fork or spade, but start digging about a foot away from the base of the plant to avoid slicing into roots.
Loosen the soil gently in a wide circle, then use your hands to pull the sweet potatoes out of the ground.
Brush off the excess dirt but don’t wash them yet because washing can introduce moisture that leads to rot.
Set any bruised or cut sweet potatoes aside to eat first since they won’t store well for long.
The healthy, intact ones are the ones you’ll want to cure and store properly.
1. Cure Them for Better Flavor
After you pick sweet potatoes, they need a curing period to convert their starches into sugars.
Curing isn’t optional if you want sweet, tasty roots because this step dramatically improves the flavor.
Place your freshly picked sweet potatoes in a warm, humid spot for about 7 to 10 days.
The ideal curing conditions are around 85°F with 85 percent humidity, but a warm kitchen corner works in a pinch.
Once cured, the skin will toughen up and any small nicks will heal over, helping them last for months.
2. Store Them in a Cool Place
After curing, move your sweet potatoes to a cooler storage area that stays around 55°F to 60°F.
Keep them in a dark, well-ventilated spot like a basement pantry or a cardboard box with holes.
Avoid storing them in the refrigerator because cold temperatures ruin their texture and taste.
Check your stored sweet potatoes every couple of weeks to remove any that start to spoil.
With proper curing and storage, you can enjoy your sweet potatoes for up to a year after harvest.
So, When Are Sweet Potatoes Ready To Pick?
Sweet potatoes are ready to pick when the leaves yellow, the vines wither, and the roots reach at least two inches thick.
You can also pick sweet potatoes when the soil temperature drops and frost threatens, even if they haven’t reached full maturity.
The best approach is to combine day counting with the visual cues and that test dig method for absolute certainty.
Remember that sweet potatoes can’t ripen off the vine like some fruits, so waiting until they’re fully mature is essential.
Now you have all the knowledge you need to know when sweet potatoes are ready to pick with confidence every single season.
So get out there, trust those plant signals, and enjoy the sweet reward of a perfectly timed harvest.
Happy digging, and may your sweet potatoes always come out of the ground at just the right moment.