How to Know When to Harvest Potatoes (2024)

Tips on how to know when toharvest potatoes. Includes different signs to look for, such as what happens to theirfoliageand flowers. Also includes information on when to harvestnew potatoesversus maincrop varieties.

One of the easiestvegetablesto start growing is the humble potato. They’re relatively simple to plant and care for and so fun todigup! Each plant, on average, can give you around eight to ten potatoes, making them a delicious and worthwhile crop. There are also dozens of different types of potatoes that you can grow. Everything from varieties bred for sweet and tendernew potatoes to oblong-shaped fingerling varieties to huge baking potatoes. Then there are the colors! Red potatoes,yellowpotatoes, purple potatoes, and multi-colored potatoes. Though most types can be grown similarly, knowing when toharvest potatoescomes down to their type and when you plant them.

Don’t worry, though — growing them is relatively easy, as is knowing when toharvest potatoes. Especially if you know which type of potato it was that you planted. Knowing when it’s time todigthem up is a breeze if you have that information on hand. You either wait for the allocated time or watch the plant for the signs it gives that the potatoes are ready. If you’ve forgotten which type of potatoes you’re growing, you can use these signs to work out when to harvest them.

Two Main Types of Potatoes

The time it takespotato plantsto produce a crop is dependent on whether the potato is anearly potatovariety or a maincrop (storage) variety.Early potatoesneed much less time from planting to harvest and grow good crops of thin-skinnednew potatoes. You tend to harvestearly potatoesin late spring to early summer since they take around eight to fourteen weeks (55-100 days) to harvest. Maincrop varieties take much longer, often around five months.

Within the early category, you have potatoes that grow faster than others. The quickest is ‘first early’ potatoes, which can give you a harvest ofnew potatoeseight to twelve weeks after planting, depending on the variety. ‘Second early’ potatoes generally take fourteen to sixteen weeks to mature, which is excellent because it staggers the harvest if you plant both first andsecond earliesin your garden. You can plant them at the same time or wait a couple of weeks to stagger the harvests more.

In the maincrop category, there are also early maincrops, ready between sixteen and twenty weeks after planting, and ones that need a little more time. Harvesting them is a little different than early varieties and will give you thicker-skinned potatoes that you can bag up and store for months.

When to Harvest FirstEarly Potatoes

My favorite potatoes to grow fit into the first early category. You can plant them two weeks before yourlast frost dateand have a crop two to three months later! Firstearly potatoesare small and tender-skinned and taste incredible in those early days of spring. You can start harvesting them when they’re about the size of an egg or leave them in an extra week or two to plump up to a larger size.

I’ve grown several varieties over the years, including Arran Pilot, Home Guard, Lady Christl, and the only firstearly potatowithred skin(that I’m aware of), Red Duke of York. My hands-down favorite is called Annabelle, a tendernew potatowith creamyyellow flesh.

I’m zone 9a and plant first earlies on or around St Patrick’s Day, but I have planted them as early as late-February before. If afrostcomes after the potatofoliageis up, it can damage them, which is why many people earth up theirearly potatoes. That means drawing soil or compost up around the plant, even completely covering thefoliage. You can also use arow coverto protectpotato plantsfromfrost.

Depending on the variety,early potatoescan be ready to harvest in as little as two months. If you’re growing a row of firstearly potatoes,digone plant up after that time and see what the yield is like. Otherwise, wait longer, or you can often refer to the flowers the plant produces. Mostearly potatovarieties will produce flowers inJune, quite pretty ones too. Many are white, but they come in purple and pink too. Once the flowers start to go over or the unopened flower buds drop, you know that the potatoes are ready to harvest. This will take anywhere from eight to twelve weeks after planting.

When to HarvestSecond EarlyPotatoes

Second Earlypotatoes take two to four weeks longer to crop than FirstEarly potatoesand include varieties such as Anya, Charlotte, British Queen, Nadine, and International Kidney (Jersey Royals). This longer cropping time comes in handy in thevegetablegarden since it means you can finish eating the first earlies before beginning to harvestsecond earlies.Second earlypotatoes take anywhere from twelve to sixteen weeks (three to four months) to harvest but are otherwise the same as first earlies. They often produce flowers and don’t store well, sodigthem up and eat them within a week. The tenderness and fresh flavor of early potatoes can fade quickly. Even if stored in the fridge or cupboard.

Secondearly potatoesgenerally produce flower buds that sometimes bloom and sometimes don’t. It’s time todigup your tender, homegrown potatoes when the buds drop or the flowers that do bloom begin to fade. At this point, theleaveswill still be green, but some may start fading toyellow. The potato crops fromsecond earliescan be like first earlies in size and tenderness. Leave them growing for longer, and the potatoes can get bigger too! There’s a fine line between bigearly potatoes with tender skinand bigearly potatoeswith thickened skin, so don’t leave them too long.

When to HarvestMaincrop Potatoes

Maincrop potatoes, also calledlate-season potatoes, are the larger storagetypes that wedig, dry, and store for use over the winter. These are thicker-skinned potatoes that we don’t eat the skin of (usually), and they take a lot longer to grow. They can be cooked as baking/jacket potatoes or peeled, fried, roasted, or boiled. In the USA, these include russet potatoes, any storing potato with brown skin and floury white flesh.Maincrop potatoescan have other skin and flesh colors, too! I grow an entirely purple potato called Purple Majesty that stores well, and King Edward, Cara, and Pink Fir Apple (a fingerling potato) are also popular UKmaincrop potatoes.

Maincrop potatoescan be planted at the same time or up to a month later assecond earlypotatoes. They need a lot more time to grow tomaturity— around 20 weeks. Over the summer, they swell and develop, resulting in harvests large in both size and quantity. You harvest main crops in late summer, typically from August to September, and you know the time is right when thefoliageon the plants begins to turnyellow. It will then wilt and dry; eventually, only brown witheredleavesandstemswill remain.

Maincrop Potato Foliage Dies Off Naturally

As they begin to die off, you can cut thefoliageoff an inch or two from the ground or wait until the plants are completely dead and brown. Wait a further two weeks beforediggingthe potatoes from this point. The tubers need this time to develop a thicker skin that will help them last longer instorage.

Maincrop potatoesmay also produce flowers and sometimes green berries (toxic, don’t eat), but these will come at the end of summer. If thefoliagestarts to die back or develop black spots before four months from planting, it may also be a case of potato blight or another potato disease. If you determine that your potatoes have blight, remove all thefoliageandstemsand either burn or throw them away. Wait two weeks, thendigthe potatotubersup. Throw any away that have black splotches or remain wet after drying.

What doPotato PlantsLook Like when Ready to Harvest

If you’re unsure about which type of potato you’re growing or when toharvest potatoesfrom it, you can do a couple of things. First, watch thefoliageand flowering cycle, and second, manually check to see the size of the potatoes at any given time.

If the potato variety produces flowers, it will be towards the end of its growing season. Keep in mind, though, that not all potato plants will produce flowers. Still,most early potatoeshave flowers and those appear in late spring to early summer. If you don’t see blossoms on your plants then, there’s a good chance that the plants aren’tearlies.

Foliagecan be a dead giveaway for knowing when potatoes are ready to harvest. Not so much with early varieties, though the lowerleavesmay start toyellowwhen ready. Withmaincrop potatoes, thefoliageandstemsabove the ground will completely die off. It happens from late August to early September, and the plants will wither into brown husks. Be aware that potato blight can cause similarfoliageto die off, but it tends to happen earlier than you’d expect.

Still stumped? Another way to check when toharvest potatoesis todigup an entire plant from the row or gently pull the soil from around the base of the plant. Either will quickly if decent-sized potatoes are waiting under the ground. Potatoes grow relatively shallowly, so you should find some just an inch or two around the base of the plant.Maincrop potatoesdon’t produce much more than pebble-sized potatoes until later in the summer. If you use this method, I’d recommend doing this from the twelve-week stage at the earliest, and only if you haven’t spotted flowers on the plant.

How toHarvest Potatoes

There are a few different ways to grow potatoes, and how you harvest them depends on how they’re growing. If you’ve planted them in the ground, use your gardenforktodigthem up. Place it a good distance from the plant, about 12-18 inches from the base, anddigfrom there. Your aim is not to spear any potatoes as you dig since you can’t store damaged potatoes. Set any damaged potatoes aside to eat on that day.

Another way to grow potatoes is undermulch; you’ll sometimes see the method referred to as no-digpotatoes. You set theseed potatoeson the soil’s surface and then cover them with a thick layer of compost orstraw. Thepotato plantsgrow right up through themulch, and the potato crop is incredibly easy to harvest. You simply push themulchaside and harvest your spuds.

Potatoes can also successfully be grown in containers. Some gardeners even prefer growing them that way! You plant oneseed potatoin a large pot,basket, or container, and when it’s finished growing, you upend the container and harvest your potatoes. Early varieties of potatoes are usually determinate, meaning they only produce a certain number of potatoes at the base of the plant. Some main crop potatoes are indeterminate, though, just liketomatoes. If you keep earthing them up, they’ll continue growing potatoes up theirstem. That’s how some people get huge harvests from a single plant.

HarvestMaincrop PotatoesasEarly Potatoes

If you cannot find potatoes specifically bred to be first orsecond earlies, you can still harvestnew potatoesfrom maincrop varieties. Beginning inJuly, use your hands to pull the soil ormulchfrom around a plant. Take just a few baby potatoes from the surface, then cover the plant back over. Taking a few potatoes from each plant won’t hurt it, and the rest of the potatoes can continue growing into bigstoragepotatoes.

Though you can harvest many main-crop potatoes as earlies, or carefullydiga few out after the plant has flowered, I think it’s best to grow types specifically bred to be earlies. They’ll crop earlier and be bred for flavor and texture. I don’t often grow maincrops, but when I do, I tend to leave them to grow into the biggies they’re supposed to.

StoringEarly Potatoes

Early potatovarieties produce delicious thin-skinned tender potatoes, but unfortunately, they don’t store well. Once youdigthem up, you can keep them in a cupboard or the refrigerator, but the flavor is best if you cook them within a week. Alternatively, you can leave first earlies to continue growing in the ground. The potatoes will initially get bigger and still have that tendernew potatoskin. However, if you leave them in the ground for too long, the skin will thicken, and the flesh texture may change.

If you have too manyearly potatoesto eat, you can temporarily leave them in the ground. Just be aware that you may need to peel them before cooking them. Alternatively, you can preserve potatoes in a pressure canner. They’re a low-acidvegetablethat needs precise handling and canning to make them shelf-safe. Pressure canners are not common in Britain and Europe but are widely used by preserving enthusiasts in North America.

StoringMaincrop Potatoes

Unlikeearly potatoes, maincrops are suitable forlong-term storage. First, you should inspect the potatoes and choose only undamaged ones forstorage. Any that are damaged or have scab should be set aside for eating relatively soon. Then dry them thoroughly (calledcuringpotatoes) before putting them in bags orcardboard boxesforstorage. Don’t wash the soil off the potatoes or it will shorten their storage time.

You cure potatoes by spreading them out in a warm, dry place such as agarageor greenhouse. You could even leave them outside in the sun for a few hours, turning them over after one side is dry. Leaving potatoes in thesunlightfor a day or two can cause them to turn green, though. Small amounts of green are harmless, but if a potato turns dark green, you want to avoid eating it.

After drying them off for a suitable time, check to see if there are any wet spots. These could be the beginnings ofrotor disease. If you find any, set them aside to cook immediately before bagging up the others.

Store potatoesin hessian or paper bags in a coolgarage,basem*nt, shed, or aroot cellarif you have one. Check them regularly to spot any signs ofrotor pests and ensure you eat the best ones first. Someone I know once tried to save the best ones for last, but by the time he got to them, the mice had already had their turn.

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