When to Harvest Potatoes at Home - From Earlies to Maincrop

09/06/2023 Rob Walter

Whether you're trying to cut down on your weekly supermarket spend or have a healthier, more sustainable lifestyle, growing your own potatoes at home is a great way to ensure you have a steady supply of this versatile veg.

In fact, it's thought that "two-fifths of people with either a garden, allotment or balcony garden are growing their own produce" as a result of all the economic uncertainty we're going through right now. If you're amongst these beginner potato gardeners, you may be wondering how and when to harvest potatoes for the best results.

To help you out, our gardening experts have answered a few of the most common questions about harvesting potatoes. 

So, let's get into it!

How Do You Know When Potatoes are Ready to Harvest?

After all your hard work planting, earthing, feeding and watering your spuds, harvesting is definitely the most exciting part of the whole process. 

Making sure you harvest potatoes at the right time is crucial for getting the maximum yield.

Since you can't visibly see the potatoes because they're underground, it can be difficult to tell when they're ready. But what you can do is scoop away some of the soil using a hand trowel so you can check the size of the potatoes.

Obviously, the full size of your potatoes will depend on the variety of potatoes you're growing, so if they're looking on the smaller side, just cover them back over and give them a few more weeks to grow.

When to Harvest First and Second Earlies

First earlies and second earlies (more commonly known as new or baby potatoes) are the easiest and most popular varieties to grow at home. They both typically take around 12 weeks (3 months) before they're ready to harvest.

First earlies will be ready for you to harvest around June and July (assuming you planted them in March), and the second earlies will be good to pull up around July and August.

Look Out for Flowers on the Early Potato Varieties

For the first and second earlies, you should also look out for flowers on top of your potato plants to indicate it's time to harvest. The tubers will start to produce small, white flowers when the potatoes are ready, and this typically happens around June.

As soon as you see these flowers, you know it's probably time to harvest your potato plants. But you should check the size of them first – early potatoes should be about the size of a hen's egg.

Second earlies will also produce flowers (but they don't always bloom). 

When the bloomed flowers begin to fade, or the buds drop, you can start your harvest. You might also notice a slight yellowing of the leaves, which is another good sign that the potatoes are ready.

When to Harvest Maincrop Potatoes

Maincrop potato plants take longer to grow and require more space because they're larger than early varieties, so they're a little less common for growing at home. But if you've got the space in your garden or allotment, it's definitely worth it!

Main crop potato seeds should be harvested around August to October when planted in mid-April, so you should wait around 4 to 5 months.

You can leave these spuds in the ground for longer if you wish, so they'll grow bigger in size, but note that the longer you leave them in the ground, the more risk they have of being eaten at by slugs.

The leaves will also start to turn yellow when the potatoes are ready to harvest, eventually wilting and dropping off. Once this happens, wait a week or two and then start to dig around the plants.

When to Harvest Sweet Potatoes

Sweet potatoes have become a household favourite for many in recent years thanks to their naturally sweet, creamy texture.

Assuming you planted your cuttings in spring, they should be ready to harvest by early autumn in around 4 or 5 months' time. Just like maincrop potatoes, the foliage will start to yellow and die back when they're ready.

How to Harvest Potatoes at Home

Once it's time to harvest your potatoes, you'll want to make sure you pull up your spuds correctly so you don't damage their skins. 

Follow these steps to get started:

Throw out any green potatoes you find – they won't be safe to eat.

When you're harvesting sweet potatoes, take extra care as their skin is more delicate.

And that's it! Now all that's left to do is store your potatoes correctly and enjoy your home-grown produce.

How to Properly Store Potatoes at Home

The next big step in the harvesting process is storing your potatoes. This is important to ensure they stay fresh for as long as possible.

You can leave your tubers in the sun for a few hours to dry out the skins and prevent rot. Once they're dried, store them in a cool, dark place where it's nice and dry – like a wooden crate, cardboard box, hessian or paper bag.

New and baby potato plants are best when they're eaten soon after harvesting, but main crop potatoes can last a lot longer. Always check them for signs of mould and rot before you cook them, however.

Rounding Up: When to Harvest Potatoes for the Best Results

Now you know all the top tips for harvesting potatoes, let's round-up with a handy table that summarises when to harvest potatoes based on their variety:

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