How to grow Potatoes

How to grow Potatoes

That great staple of the British diet, the potato, is also understandably one of the most widely cultivated crops. Relatively undemanding and easy to grow, it is a reliable vegetable that has won a spot in almost every kitchen garden. 

The potato year starts in the depths of midwinter when the young tubers, known as seed potatoes, are left to sprout. They’re planted outside later in the spring. If you’re wondering ‘how long to grow potatoes’, there’s no single answer. More than 400 varieties are available to British growers, with varieties grouped into three main categories according to the time they take to mature. 

The harvesting season starts as early as late May with the ‘first earlies’, and continues well into autumn with the ‘maincrops’. In between, the ‘second earlies’ will give a steady supply of tubers right through summer. If you’re a little unsure of your growing prowess, you can invest in potato growing kits to help you along.

The potato has been adapted for modern lifestyles, with growing methods allowing virtually everyone to try their hand at the crop, no matter their circumstances or space restrictions. Growing potatoes in bags (Monty Don does this), pots, tubs and containers has become common practice, while new varieties are available to thwart potato blight. 

Modern techniques even allow for a second planting in late summer for a crop of potatoes in late autumn, raising the possibility of home-grown spuds for Christmas.

Preparing the ground for potatoes

Potatoes are often credited with breaking up the ground for later crops to follow: it’s the preparation of the soil and the lifting of tubers that does this. Potatoes are very heavy feeders, so they need rich earth, ideally in a sunny part of the plot.

They prefer soil to be on the acidic side with a high pH level, so avoid growing potatoes in an area where you’ve recently applied low-pH lime. Lime is often used to combat the brassica-infecting disease, clubroot.

Frost can damage young growth, severely setting back the crop, so pick a site that’s clear of any frost pockets. Begin preparing the soil by digging in ample quantities of well-rotted manure or garden compost. Ideally, do this the winter before planting, and at the latest as you begin to ‘chit’ your seed potatoes.

Add about a bucketful of the organic matter for every square metre. About a fortnight before planting your potatoes, add a good sprinkling of organic fertiliser such as chicken manure pellets to give an extra boost of nutrients.

How to chit potatoes

You should order your seed potatoes as soon as possible, to allow enough time for them to sprout – a process called ‘chitting’. The idea is that they make a quicker start into growth when they’re planted outside, and will therefore produce a heavier crop.

To get chitting underway, take the seed potatoes out of their packaging and lay them out in trays, with the ‘eyes’, or buds, facing upwards. Egg boxes make excellent makeshift trays and will hold each potato in place. Start all this about six weeks before planting time in a cool but frost-free location – a spare room with the heating turned off is a good bet. That usually means late January in warmer parts of the UK, and late February in cooler areas.

How to plant potatoes

Once the shoots are 1-3cm in length, the seed potatoes can be planted outside. The ideal seed potato is the size of an egg, and will have two or three healthy sprouts. First earlies should be planted outside from early April or as soon as the soil has warmed a little. Second earlies and maincrops can follow two to three weeks later.

You can either use a hoe to draw a wide drill about 10cm deep in the soil, or dig individual planting holes using a hand trowel. Space first earlies 30cm apart and leave 45cm between rows. Second earlies and maincrop potatoes produce bigger plants and need a little more room, with 38cm spacings and 75cm between rows. 

Carefully place a potato into each position, taking care not to damage the shoots. Cover them with at least 2cm of soil, or draw up earth from in between the rows using a hoe. This will create a shallow ridge over the lines of potatoes.[Text Wrapping Break][Text Wrapping Break]

Growing first early potatoes

First earlies may need some protection from spring frosts. Keep horticultural fleece to hand and place it over emerging potato shoots if frost threatens, or draw up soil around the shoots using a hoe. Once the shoots reach 25cm in height they will need regular ‘earthing up’.

This simply involves drawing the soil up around the potato stems, leaving just the tips of the foliage showing each time. Repeat the process at fortnightly intervals until a clear ridge has formed around the plants and the top growth meets in between the rows.

Potato lovers can (and should) grow some of each group of potatoes. First earlies are a good choice for those with limited space as they can be planted closer together. They will also be out of the ground before potato blight threatens later on in the summer, freeing up room for a second crop in the same season. Maincrop potatoes, however, offer a heavier harvest and the tubers tend to be much better for storage.

Growing potatoes in containers

Like many vegetables, potatoes make excellent container crops, as long as the right conditions and varieties are selected. Select a first or second early such as ‘Mimi’ or ‘Charlotte’, as they will produce smaller plants than maincrop varieties. Use a purpose-made potato barrel, or grow potatoes in sacks or good-sized containers that are at least 30cm wide and deep. 

It’s easy to grow potatoes in a bag or in potato grow sacks. Simply fill your potato grow bag, container or tub with a 10cm depth of compost, then position two to three seed potatoes on top. Cover them with a 15cm layer of compost and water them in.

When the shoots reach 15cm in height, begin ‘earthing up’ the potatoes by adding compost to leave just the shoot tips showing. Continue to add compost as the shoots push upwards, leaving the tips clear each time to enable them to grow on. Water regularly in hot, dry weather, and apply an organic liquid feed to help the tubers swell to a good size. The potatoes will be ready to harvest when the plants flower, or not long afterwards.

The ideal time to plant potatoes is from late January in a heated greenhouse, or late February in a cool one for a crop as early as Easter. Specially held-back seed potatoes from seed merchants can be planted in late August or September for a crop in late autumn. If you’re growing potatoes in pots in the UK, keep these containers in a sheltered position that’s free from frost. You may even be able to enjoy a few of your home-grown spuds at Christmas!