How to know when to harvest potatoes: it's based on whether they're an early potato or main crop and what happens to their foliage and flowers #lovelygreens #growyourown #gardeningtips
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How and when to harvest potatoes: know when to dig potatoes up

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Knowing when to harvest potatoes is based on whether they’re an early potato or maincrop, time in the ground, and what happens to their foliage and flowers

One of the easiest edibles to start off with is the humble potato. They’re relatively low-maintenance, can help cultivate the soil, and will also suppress any weeds that try to compete with them. They’re also very fun to dig up and eat! But when are potatoes ready to harvest? This is probably the most taken for granted kitchen gardening knowledge you’ll find. Seasoned gardeners will ‘just know’ when the plant is ready. When you’re just starting out it’s a bit of a head-scratcher.

The answer lies in which type you’ve planted. The vast majority available will fit into the categories of ‘First Early’, ‘Second Early’, and ‘Maincrop’. Read on to know what to look for when it’s time to harvest potatoes.

How to know when to harvest potatoes: it's based on whether they're an early potato or main crop and what happens to their foliage and flowers #lovelygreens #growyourown #gardeningtips
Main crop King Edward potatoes dried and ready for storage

First Earlies

In my opinion, the best type of potato to grow is one that fits into the ‘First Early’ category. These include the Red Duke of York, Lady Christl, Arran Pilot, and scores more. This year I’ve grown Pentland Javelin which is a type that matures slightly later than other First Earlies.

‘First Earlies’ are one of the earliest garden crops to mature. You plant them from St Patricks Day to mid-March and then dig them up around 10-12 weeks later. Typically from June to July but sometimes earlier. They’re easy to grow, don’t tend to suffer blight, taste tender and delicious, and fun to dig up in early summer.

How to know when to harvest potatoes: it's based on whether they're an early potato or main crop and what happens to their foliage and flowers #lovelygreens #growyourown #gardeningtips
Potato flowers beginning to drop indicates that it’s a good time to dig up first early and second early potatoes

Look for potato flowers

The way you tend to know that first earlies are ready is by their flowers. Early potatoes generally produce flower buds that sometimes bloom and sometimes don’t. It’s time to dig up your tender, homegrown potatoes when the buds drop or the flowers that do bloom begin to fade. Another good indication is seeing unopened flower buds dropping from the plant. At this point, the leaves will still be green but some will begin fading to yellow. The potatoes from earlies will be about the size of an egg with skins so tender that they’ll melt in your mouth.

If you’re not sure about if they’re ready, gently dig around a plant and look for potatoes. If they’re the size of an egg or larger, you can start harvesting. First earlies left in the ground will continue to grow. That means that if you’re not quite sure if they’re ready to harvest, just leave them in a little while longer. Not all early potatoes are great for storing but some are, so do your research before you buy potato varieties.

How to know when to harvest potatoes: it's based on whether they're an early potato or main crop and what happens to their foliage and flowers #lovelygreens #growyourown #gardeningtips
First and second earlies are thin-skinned and tender and harvested about 70-90 days after planting.

Second Earlies

Potatoes that fall into the ‘Second Early’ category include Nicola, Maris Peer, Jazzy, and Kestrel. They differ only in one way from first earlies — they mature about three weeks later.

As for planting times, you can get them in the ground at the same time as first earlies but it’s better to wait. The traditional day to plant them in most of the UK (zone 7-8) is the first day of spring, in late March. Just think about it, if you plant them at least two weeks after your first earlies then the harvests are staggered by five weeks. That gives you time to eat your first crop before another massive harvest is ready.

Use the same indications for harvest as first earlies and look for blossom drop. By the way, how gorgeous are potato flowers? They come in all different colors and potatoes were actually grown in Europe as ornamentals before they were grown as food crops.

How to know when to harvest potatoes: it's based on whether they're an early potato or main crop and what happens to their foliage and flowers #lovelygreens #growyourown #gardeningtips
The humble potato flower. You know early potatoes are ready when the blossoms begin to fade.

Maincrop Potatoes

Think of a massive baking potato and it’s most likely a maincrop, sometimes called storing potatoes. Varieties in the UK include Cara, King Edward, Pink Fir Apple, and Purple Majesty. In the USA, they’ll be Russet varieties.

Maincrop potatoes are planted at the same time or up to a month later as second early potatoes. They need a lot more time to grow — about 20 weeks. Over the summer they swell and grow resulting in harvests large in both size and quantity.

Though you can harvest many main-crop potatoes as earlies, or carefully dig a 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 as an early. Leave maincrops to grow into the biggies they’re supposed to and store them for use over the winter.

Harvesting Maincrop Potatoes

You harvest main crops in late summer, typically in August to September and you know the time is right when much of the foliage on all your plants begin to turn yellow. It will then shrivel up and turn brown and dry, and eventually only shriveled leaves and stems will be left. At any time during this process, cut the plant off about an inch from the ground and leave the tubers in the ground for a couple of weeks before digging them up. This helps harden up the skin and makes them better for storing.

This is natural die-back and will be different from a disease. If you see black spots on the foliage or if the die-off is only affecting some of your plants then you should investigate potato diseases. If the issues are happening before the 20-week mark then it’s also an indication that something is wrong.

Natural potato plant die-off can look a lot like a disease

Storing Maincrops

Unlike early potatoes, you can store maincrops for months at a time. First, you should dry them completely before putting them in bags or boxes for storage. Any wet areas could introduce rot, or actually be rot. Spread them out in a garage or greenhouse, or outside in the sun, turning them over after one side is dry. Leaving potatoes in the sun for any longer than a day or two can cause them to turn green. Small amounts of green are harmless but if a potato turns dark green, you want to avoid eating it.

Store maincrop potatoes in a cool garage or shed and make sure to eat the best ones first. A friend once tried to save the best ones for last but by the time he got to them, the mice had already had their turn. If you’re looking for recipe ideas for larger second earlies, try Hasselback potatoes. With their tender skin, you don’t even have to peel them.

How to know when to harvest potatoes: it's based on whether they're an early potato or main crop and what happens to their foliage and flowers #lovelygreens #growyourown #gardeningtips

How to know when to harvest potatoes: it's based on whether they're an early potato or main crop and what happens to their foliage and flowers #lovelygreens #growyourown #gardeningtips

13 Comments

  1. Fantastic advice for me…. the novice. I have planted casablanca, desiree and Charlotte potatoes in tubs and they are all just about ready for harvest. Which one should I dig up first?

    1. Hi Liz, each of the potatoes you’re growing has a different time to harvest. Casablanca are a first early and are the first to harvest. Then your second early, Charlotte, followed by your main crop, Desiree

  2. I’m new to this I put my potatoes in a nice size bucket and now they are beautiful green foliage and I can’t tell when to pull them. When. Should the flowers pop up. Also, can I start another pot while waiting.

  3. St Patrick’s day is March 17th. Mid march would be the ides of March which is the 15th. Depending on where you live, you can plant potatoes from mid-March until the middle of June. it depends on your climate. here we still often have foot or more high of snow and can not get into the ground in March. We have even had multiple blizzards in March. I usually plant a lot of my seed item indoors On St Patrick’s day and do my potatoes outdoors when the ground permits

  4. I’ve planted both earlies (arran pilot) and maincrop (king edward) in raised beds mid-march. but i’m now confused by the foliage. what i thought was maincrop is only 12-15in high and a few are flowering, but the other (earlies) is now 24in high but no flowers. I would have expected the earlies to flower first. Have I got them mixed up?

  5. Believe me, I did not know what I would give to plant potatoes in a small area as a home garden, I imagined that it would depend on the environment, land and weather, living and learning, I loved your tips …. Success

  6. I grow vegetables, and they grow aerated on benches, how much do I need depth to plant the Maincrops, and can only plant in winter for the summer?
    If you plant for example in the summer of harvesting?
    How long until the harvest?

    1. I don’t think that summer planted potatoes would produce very much — maincrops need a long season. Potatoes won’t grow in the winter so that wouldn’t work either. This post is more about knowing when to harvest spuds. If I were you I’d research more on growing them.

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