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Potatoes are ready to pick when the plants have flowered, the foliage has begun to yellow and die back, and the skins on the tubers are firm enough that they don’t easily rub off with your thumb.
Timing your potato harvest is a bit of an art, and knowing when do you know potatoes are ready to pick hinges on a few clear visual and physical cues.
You’ll know potatoes are ready to pick when you see the right balance between the top growth of the plant and the maturity of the spuds hiding underground.
In this post, we’ll walk you through the exact signs that tell you when potatoes are ready to pick, whether you’re after new potatoes or full-sized storage spuds.
Let’s dig in and get those taters out of the soil at the perfect moment.
When You Know Potatoes Are Ready To Pick: The Key Indicators
The main answer to when do you know potatoes are ready to pick comes down to watching the plant’s life cycle, and then doing a quick test dig.
Potatoes are ready to pick at two different stages, and each stage has its own set of clues.
For early “new” potatoes, you’ll know potatoes are ready to pick about two to three weeks after the plants have finished flowering.
For mature, storage-ready potatoes, you’ll know potatoes are ready to pick when the entire above-ground plant has largely died back and turned brown.
Let’s break down these signs so you can confidently decide when potatoes are ready to pick in your own garden.
1. Flowering Signals the Start of Tuber Growth
The first clue that helps you determine when potatoes are ready to pick is the appearance of flowers on the plant.
When your potato plants start blooming, it signals that the plant is channeling energy into developing the tubers below the soil.
Don’t rush to harvest just because you see flowers, as the potatoes are still quite small at this stage.
But this flower stage is your starting point, so mark your calendar and start counting the days.
From the bloom time, you’ll know potatoes are ready to pick for new potatoes in roughly two to three weeks.
New potatoes are thin-skinned, sweet, and perfect for immediate eating, but they won’t store well because their skins are so delicate.
If you want to know when potatoes are ready to pick for a summer treat, this flowering-to-three-weeks window is your sweet spot.
2. Foliage Yellowing and Die-Back for Mature Spuds
The most reliable answer to when do you know potatoes are ready to pick for full-sized, storage potatoes is to watch the leaves and stems.
As the season progresses, the potato plants will naturally start to yellow, flop over, and eventually dry out completely.
When about 70 to 80 percent of the foliage has turned yellow and is starting to die back, you’ll know potatoes are ready to pick.
This die-back is the plant’s way of telling you that the tubers have stopped growing and are now maturing their skins.
Don’t harvest too early at this stage, as skins need time to set, which is why waiting for the foliage to die back is critical.
When the tops have completely withered and turned brown, you’ll know potatoes are ready to pick for long-term storage.
At this point, the skins have thickened and cured naturally in the soil, giving you the best chance at keeping them for months.
3. The Thumb Test: Checking Skin Firmness
Beyond just looking at the foliage, you can physically verify when potatoes are ready to pick by doing a simple scratch test.
Gently dig around the base of a plant and pull out one of the larger potatoes to inspect it.
Take your thumb and lightly rub across the skin of the potato.
If the skin easily scrapes off and feels thin, then you’ll know potatoes are ready to pick for new potatoes, but not for storage.
If the skin stays firmly attached and doesn’t rub away, then you’ll know potatoes are ready to pick for mature, storage-grade spuds.
This test is a foolproof way to remove any guesswork, as it directly tells you the state of the tuber’s skin.
Potatoes are ready to pick when the skin is thick enough to resist gentle pressure, which happens a couple of weeks after the foliage dies back.
You’ll know potatoes are ready to pick when this test confirms that the skins have set properly.
4. Time from Planting as a Backup Guide
If you’re still unsure when do you know potatoes are ready to pick, you can rely on days-to-maturity for your specific variety.
Early varieties are typically ready to pick about 70 to 90 days after planting, and you’ll know potatoes are ready to pick for new spuds at this time.
Maincrop varieties need more patience, usually taking 100 to 130 days, and you’ll know potatoes are ready to pick for storage at the end of that range.
Check your seed packet or plant tag for the exact number of days your potato variety needs.
Use this timeline as a rough guideline, then always pair it with the foliage and thumb tests to confirm.
The calendar will help you get close, but the plant’s condition is the final word on when potatoes are ready to pick.
How to Pick Potatoes Without Damaging Them
Once you’ve determined when potatoes are ready to pick, the next step is getting them out of the ground safely.
Use a garden fork or a shovel, and insert it well away from the plant’s base to avoid slicing into the tubers.
Gently lift the soil from the side, then use your hands to sift through the dirt and pull out the potatoes.
Handle them gently, as even mature potatoes can bruise easily if dropped or tossed around.
For new potatoes, harvest them right before you plan to eat them since they don’t keep well at all.
For mature potatoes, leave them on the soil surface for a couple of hours to allow any soil to dry and brush off.
If the weather is sunny and hot, don’t leave them exposed for too long, as direct sunlight can turn them green and toxic.
Instead, move them to a shaded, dry spot and let them cure for a week or two before storing.
So, When Do You Know Potatoes Are Ready To Pick?
You know potatoes are ready to pick when the plant’s flowers have faded, the foliage is yellowing or dead, and the skin on the tubers resists rubbing.
Potatoes are ready to pick for new spuds about two to three weeks after flowering, when the skins are thin and easily scraped.
Potatoes are ready to pick for storage when most of the leaves have died back and the skins have set firmly on the tubers.
Do a test dig and the thumb test to confirm, and you’ll know potatoes are ready to pick with total confidence every single season.
By watching the plant and feeling the skins, you’ll always harvest at just the right time.
Happy digging, and enjoy the reward of perfectly timed, homegrown potatoes fresh from your own soil.