How to grow potatoes

Potatoes are a traditional veg plot staple, easy and fun to grow, producing a plentiful crop in summer or early autumn. Whether you’re new to growing potatoes or have been doing it for years, digging up your buried bounty is always a thrill. And eating your first new potatoes of the season, steamed and served with butter or mint, is a highlight of early summer.

Harvesting your own potatoes is like digging for buried treasure

Potatoes are grown from specially prepared ‘seed potatoes’ (small tubers), usually planted in spring. With early varieties, the seed potatoes can be ‘chitted’ (or encouraged to sprout) before planting, to get them off to a head start and produce an earlier crop. As the plants grow, soil can be gradually piled up around the stems, known as earthing up, to bury the developing tubers. If you don’t have room for a whole row of potatoes, you can grow just a few in a small bed or large container. You can even grow a winter harvest by planting in a large tub in late summer, then protecting the plants from frost in a greenhouse or sunny porch.

Potatoes are usually easy and reliable croppers, but they can be affected by several diseases, the most notorious being the fungal disease blight. However, this is less likely to affect early varieties and is less prevalent in dry summers.

With so many colours and flavours to tempt you, how can you resist growing potatoes?

Potato varieties are classed as either earlies or maincrops:

• Early varieties (first or second earlies) – are ‘new potatoes’, small, sweet and delicious. They’re faster growing, ready to harvest in as little as 12 weeks. The plants take up less space, so are useful in smaller plots, and can be grown in containers. As they’re harvested by midsummer, they free up space to grow another crop, such as courgettes or beans, for the rest of the summer 
• Maincrop varieties are in the ground a lot longer, through to late summer or early autumn. They produce a larger harvest and bigger individual potatoes, ideal for roasting and baking, and can be stored for use in winter  

When choosing, look in particular for varieties with an RHS Award of Garden Merit (AGM) – these performed well in trials, so should grow and crop reliably for you. See our list of AGM fruit and veg and our Recommended Varieties below. You can also see many crops, including potatoes, growing in the veg areas at all the RHS gardens, so do visit to see how they’re grown, compare the varieties and pick up useful tips.

Potatoes are mainly planted in spring, over several weeks, according to the type of variety:

• First earlies – plant around late March
• Second earlies – plant in early to mid-April
• Maincrops – plant in mid- to late April

The timing also depends on where you are in the country – plant slightly later in colder regions and earlier in milder ones. To give your potatoes an early start, you can ‘chit’ or sprout the tubers before planting (see below), so growth gets underway more quickly.

There are also a couple of other planting options, to extend the cropping season:

• To grow an extra early crop – plant chitted seed potatoes of early varieties at the beginning of March, into large containers in a frost-free greenhouse. Keep them indoors in good light for a crop by about mid-May
• To grow a winter/Christmas crop – plant prepared (cold-stored) seed potatoes in July or early August, into a large container in a greenhouse or bright frost-free location. Keeping them indoors also protects them from blight

You can harvest from early summer to autumn, if you grow early and maincrop varieties

Early potatoes and maincrop potatoes mature at different times over the summer. Harvest times can also vary across the UK and from year to year, depending on the weather. But as a general guide:

• First early varieties should be ready to lift in June and July
• Second earlies in July and August
• Maincrop varieties from late August through to October

With earlies, wait until the flowers open or the buds drop. The tubers should be the size of hens’ eggs. With maincrops, start lifting them in late summer for immediate use. You can leave them in the ground until needed, and they will keep growing larger, but the longer they’re in the soil, the more likely they are to get damaged by slugs.

Dig up potatoes carefully, inserting your fork at least 30cm (1ft) away from the base of the plant to avoid spearing the tubers. Discard any potatoes that are green, as they’re potentially poisonous. If you only want a few potatoes at a time, try digging down carefully beside a plant with a trowel – you should be able to remove a few individual potatoes without disturbing the plant’s roots, so it can continue growing.

Potatoes grown in containers are really easy to harvest, without the risk of accidentally damaging them – gently tip out the contents and simply pick out your potatoes by hand.

Early potatoes are best used as soon as possible after harvesting. Maincrops can either be used fresh or stored for several months and eaten gradually when needed through the winter. If you want to store maincrop potatoes, delay harvesting until the leaves turn yellow, then cut off and remove all the top growth. Wait for 10 days, then dig up the tubers and leave them in the sun for a few hours to dry, then brush off the soil.

Potatoes are easy to grow and usually produce a large, reliable crop. However, they can be affected by several diseases or be eaten by various soil-dwelling creatures such as slugs, which particularly like to tunnel into maincrop tubers during damp autumn weather. Blight can be a wide-spread problem in some summers, depending on the weather, but you can still usually harvest and eat the crop if you act quickly, although the potatoes won’t be suitable for storing. 

To avoid the build-up of problems in the soil, grow potatoes in a new position each year – see our guide to crop rotation. Some potato varieties are also less susceptible to certain diseases. See Common problems below for more advice on tackling the main growing issues.