When to Harvest Potatoes: 3 Signs It’s Time to Dig

Your potato plants are turning yellow, the vines are flopping over, and you’re itching to see what’s hiding beneath the soil. But dig too early, and your potatoes might not store well. Leave them too long, and a spell of wet weather or an early freeze could spoil the harvest.

Knowing when to harvest potatoes comes down to recognizing a few signs rather than relying on one particular date.

Flowers can tell you when to start checking for new potatoes, dying vines signal the end of the growing season, and firm skins show that mature potatoes are ready for storage.

Once you know what to look for, harvesting becomes much easier. And there’s something especially satisfying about lifting that first forkful of soil and discovering what your plants have been growing all season.

When to Harvest Potatoes: 3 Signs to Watch

Before you grab your garden fork, take a look at the plants. These three signs will help you decide whether it’s time to dig.

1. Flowers appear on the plants. This is a useful signal to start watching for new potatoes. About two to three weeks after flowering begins, check whether the tubers are large enough for fresh eating.

2. The leaves yellow and the vines die back. When the entire plant has dried out naturally, the potatoes have generally finished growing. This is the main signal to begin preparing for a storage harvest.

3. The potato skins no longer rub off easily. A firm skin that stays attached when rubbed with your thumb is one of the most reliable signs that mature potatoes are ready to lift and cure.

Quick Potato Harvest Timing Guide

What You’ll Need

Harvesting potatoes doesn’t call for much special equipment. Chances are, you already have most of what you need in the garden shed.

• Garden fork or spading fork: A good choice for loosening soil around potatoes without cutting through them.
• Hand trowel: Handy for checking a few tubers or working in containers.
• Bucket or garden basket: For collecting potatoes without piling them too deeply.
• Tarp or shallow tray: Gives you somewhere clean and shaded to sort the harvest.
• Soft brush or dry cloth: For removing loose dirt without washing the potatoes.
• Breathable crates or boxes: Useful for curing and storing mature potatoes.

If you’re planning to keep potatoes through winter, you’ll also need a cool, dark spot with decent airflow.

One thing to keep in mind: This guide covers regular potatoes, not sweet potatoes. The two crops need different curing conditions, so don’t treat them the same after harvesting.

Step 1: Decide Whether You Want New Potatoes or Storage Potatoes

Before picking up your garden fork, decide what you’re hoping to bring into the kitchen.

Maybe you’d like a handful of little potatoes for dinner. Or perhaps you’ve grown a whole bed and want enough to keep you supplied well into winter.

Both are worth looking forward to, but you won’t harvest them at the same stage.

Harvesting New Potatoes

New potatoes aren’t a special variety. They’re simply regular potatoes dug before they’ve finished growing.

They’re small, with delicate skins and tender flesh. Boiled or roasted with a little butter and fresh herbs, they’re hard to beat.

You can usually begin checking for them a couple of weeks after the plants start flowering.

How Big Should New Potatoes Be?

For fresh eating, tubers around 1 to 2 inches in diameter are a useful size to aim for.

They don’t have to reach that exact measurement, though. Some gardeners prefer smaller baby potatoes, while others let them grow a little larger.

If you gently uncover one and find potatoes barely bigger than marbles, give the plant another week or so if you’d prefer a more substantial harvest.

Taking a Few Without Digging the Whole Plant

In loose garden soil or a grow bag, you may be able to reach gently beneath a plant and feel around for a few small tubers.

Ease them away without pulling up the entire plant, then tuck the soil back around any remaining potatoes and roots.

It doesn’t always work neatly, especially in heavy soil, but it’s a useful way to enjoy a few early potatoes while leaving the rest to grow.

Just remember that every potato you pick now is one that won’t get any bigger.

And don’t save these delicate little potatoes for winter. They’re much better eaten fresh, ideally within about a week.

Harvesting Potatoes for Long-Term Storage

For potatoes you want to store, patience usually pays off.

As the crop matures, the skins toughen and become better able to handle digging, sorting, and storage.

A potato might look enormous when you lift it, but that doesn’t necessarily mean it’s ready for the storage crate.

If the skin rubs away easily, it may need more time.

Step 2: Watch Your Potato Plants for Signs They’re Ready

The days-to-maturity figure on a seed potato label is a useful starting point, but it isn’t a deadline.

A chilly spring can slow things down. So can poor growing conditions. In a good season, the same variety may develop a little faster.

Rather than counting days alone, take a look at what your plants are doing.

Flowers Are a Clue That New Potatoes Are Developing

When potato plants begin flowering, there’s a good chance tubers are already developing beneath them.

If you’re after new potatoes, give them another two to three weeks, then carefully check beneath one plant.

You may find several small potatoes ready for the kitchen.

But What If Your Plants Never Flower?

Don’t be surprised. Some potato varieties produce only a few blossoms, and others may not flower at all.

That doesn’t mean there’s nothing growing underground.

For many early varieties, around 60 to 70 days after planting is a reasonable time to begin checking, although the exact timing depends on the variety and growing conditions.

Loosen a little soil beside one plant and see what you find. It’s far more useful than waiting for flowers that may never appear.

Yellowing Leaves and Dying Vines Signal Maturity

If you’re growing potatoes for storage, watch what happens to the foliage as the season winds down.

The lower leaves often turn yellow first. Then the stems begin to droop, the remaining leaves lose their color, and eventually the entire plant dries out.

This is usually a normal part of the potato plant’s life cycle.

Once the vines have died completely, leaving the potatoes in the ground for another two to three weeks can help their skins finish toughening.

But you don’t have to wait exactly three weeks. The skins may set sooner, especially if the plants have been declining gradually.

Check a few tubers rather than assuming every crop needs the same amount of time.

What If Frost Is Coming?

A light frost can knock back potato foliage without necessarily damaging the tubers underneath.

But once freezing temperatures reach the potatoes, you risk losing part of the harvest.

If a hard freeze is on the way, check the skins and dig mature potatoes before the soil freezes.

Wet conditions matter too. Potatoes sitting in soggy ground after the vines have died are more likely to develop problems than those in reasonably dry soil.

Sometimes the sensible choice is to harvest a little early rather than leave a good crop in worsening conditions.

Step 3: Test Whether the Potato Skins Are Ready

Before digging an entire bed of storage potatoes, there’s a simple check worth doing.

It’s called the skin-set test.

When potatoes have properly matured, their skins cling tightly to the flesh. On an immature potato, that outer skin may slide or feather away when you rub it.

The difference is easy to see once you’ve tried it.

How to Do the Thumb-Rub Test

You only need a few potatoes from different parts of the bed.

If the skin rubs off: The remaining potatoes probably need more time before long-term storage. Leave them underground for another 7 to 14 days if conditions allow.

If the skin stays firmly attached: That’s a good sign the potatoes have matured and are ready to harvest.

Use the sample potatoes you’ve already dug for cooking rather than putting them back into the soil.

Keep in mind that this test is for storage potatoes. New potatoes naturally have thin skins, and that’s part of their appeal.

The important point: Skin firmness matters more than a fixed number of days after flowering or vine dieback. Let the potatoes themselves help you decide when to dig.

Step 4: Dig Your Potatoes Without Damaging Them

This is the fun part.

You lift the first forkful of soil and spot a couple of potatoes. Then another appears, followed by one hiding right at the edge of the hill.

It’s amazing how much a potato plant can produce out of sight.

The only frustrating part is accidentally putting a fork tine straight through one of the biggest tubers.

A little patience while digging makes a difference, especially when you’re harvesting potatoes for storage.

How to Harvest Potatoes from Garden Beds

Pick a day when the soil is reasonably dry and easy to work.

Push your garden fork into the soil about 8 to 12 inches away from the base of the plant.

Lift gently, loosening the soil rather than pushing the fork toward the middle of the hill.

Once the soil breaks apart, use your hands to find the potatoes.

Work outward, not straight down.

Potatoes don’t always stay close to the original stem. Some can develop farther out than you expect.

For new potatoes, remove only what you need and leave the rest of the plant as undisturbed as possible.

For mature potatoes, lift the whole hill and check carefully for smaller tubers left behind.

And go easy when dropping potatoes into your basket. A fall that seems harmless can leave a bruise beneath the skin.

How to Harvest Potatoes from Grow Bags and Containers

One of the pleasures of growing potatoes in bags is how straightforward harvest day can be.

Spread a tarp on the ground and carefully tip the contents of the container onto it.

Then work through the potting mix with your hands.

Check the bottom and sides before gathering up the used soil. Smaller potatoes have a habit of turning up where you least expect them.

If you’re only collecting a few new potatoes, you may be able to reach into the bag without emptying it.

Keep Freshly Dug Potatoes in the Shade

Don’t leave harvested potatoes sitting in the sun while you finish the row.

Light exposure can cause greening and increase levels of naturally occurring glycoalkaloids, including solanine.

A shaded basket, covered porch, or sheltered tarp is a better place for freshly dug potatoes.

Leave the loose dirt on them for now. There’s no need to wash them straight out of the ground.

Once you’ve collected everything, take a few minutes to sort the harvest before curing.

Step 5: Sort Your Potatoes Before Curing

After a good harvest, it’s tempting to put everything into one big crate and deal with it later.

But one damaged or rotting potato can cause trouble for the rest, especially when the crop is being stored for months.

Sorting doesn’t take long, and it makes the next steps much easier.

Potatoes to Store

Choose firm potatoes with properly set skins.

They should be free from deep cuts, soft patches, obvious disease, or serious bruising.

These are the potatoes worth curing and saving for the months ahead.

Potatoes to Eat First

Keep potatoes with small fork nicks, minor scratches, or delicate skins separate.

If they’re otherwise healthy, they’re usually fine for cooking after trimming away any damaged spots. They just aren’t the best candidates for long storage.

New potatoes belong in this group too.

There’s nothing wrong with having a few potatoes that need eating right away. That’s a good excuse to make something with the fresh harvest.

Potatoes to Discard

Throw away potatoes that are rotten, leaking, foul-smelling, or badly damaged.

Pay attention to green areas as well.

A very small surface patch may sometimes be removed generously, but potatoes with extensive greening, green flesh beneath the skin, or a bitter taste are best discarded.

Cooking won’t reliably remove the potentially harmful glycoalkaloids associated with greening.

Keep the sorting simple:

• Store: Firm, undamaged potatoes with mature skins.
• Eat first: New potatoes or those with minor damage.
• Discard: Rotten, badly damaged, or extensively green potatoes.

Do your sorting in the shade while the potatoes are still spread out. It’