Potatoes are an easy and rewarding crop to grow. You don’t even need a big garden – you can grow potatoes in a large pot, or a purpose-made potato barrel or sack.
There are hundreds of varieties of potatoes out there, but they come under four main categories – first earlies, second earlies, maincrop and salad. First earlies include varieties such as Rocket, Foremost and Epicure. These are good potatoes to grow in containers, as they take up less room than the larger, later maincrop varieties, and they are ready in about 10 weeks. Second earlies include Estima, Wilja and Kestrel varieties, and take 16-17 weeks to mature.
Maincrop potatoes require more space and time to grow. They include varieties such as Desiree, Romano and Maris Piper, and take 18-20 weeks to mature. Salad potatoes are another good type for growing in containers, as they are naturally small. Varieties include Pink Fir Apple, Charlotte and Maris Peer.
When choosing potato varieties you should keep in mind how you plan to use them in the kitchen – some potatoes have a firm, waxy texture and are good for boiling and salads, whereas others are fluffy and floury, perfect for roasting or mashing. When you buy your seed potatoes the garden centre should be able to tell you which varieties are suitable for the cooking method you have in mind.
If you plan to store your crop for use over winter, the later maincrop varieties are much better suited to this purpose.
Once you’ve bought your seed potatoes, it is traditional to ‘chit’ them before planting. This is simply encouraging the seed potatoes to start sprouting. You may have noticed that if you store a bag of potatoes for too long they start to sprout – chitting is making this happen on purpose!
You can buy your seed potatoes and start chitting them from February – about 6 weeks before planting. You need a cool, light, well-ventilated space to store your potatoes while chitting. Egg boxes are really good for laying the potatoes out. If you look at your seed potatoes, you’ll see they have a few little ‘eyes’ on them, and one end is more rounded or ‘blunt’ than the other. Set your potatoes in egg boxes or a tray with the blunt end uppermost.
You can start planting your potatoes out from March, depending on the weather. It is important to wait until the last frost is over and the soil is warm enough. Old farmers have all sorts of arcane methods for knowing when the soil is warm enough, but if you wait until after Easter you should be okay.
Dig a trench about 15cm (6in) deep, and put a layer of compost in the bottom of the trench. Then put your chitted potatoes in the trench with the green shoots pointing upwards. First earlies should be planted 30cm (12in) apart with 40-50cm (16-20in) between rows, while second earlies and maincrops should be about 38cm (15in) apart with 75cm (30in) between rows.
Gently cover the potatoes with soil and water well. As soon as you see shoots starting to appear, cover the row with a ridge of fresh soil. Do this a few times as the potato plants grow, as it encourages growth and protects the baby potatoes that are growing near the surface.
Water the plants in dry weather. If the weather is wet during July, your potatoes can be subject to a disease called blight. You can spot this by black spots appearing on the foliage. If you notice any, remove the infected foliage (don’t compost it). You can protect against blight by spraying the plants with Bordeaux mixture.
Early and salad potatoes can be lifted as soon as the plants have grown to their full size – when the flowers start to open is a good indicator that it’s time to harvest your early potatoes. Second earlies and maincrops can be left in the ground much longer – wait until after the flowers have gone before you start to lift them, then you can harvest as needed right up until Christmas. As the weather starts to get colder, protect the plants with cloches, fleece or straw, or lift the potatoes and store indoors. With second and maincrop varieties, if you cut the greenery off at ground level two weeks before you want to harvest the tubers, it will allow them to toughen up and the skin to fully form.
When harvesting, put your fork into the ground about 30cm (12in) away from the plant stem. Gently lift the plant up using your fork, and you should see some potatoes appear! Keep digging until you are sure you have all the tubers. Make sure you take out even ones that are too tiny to cook, as they may start to grow next year if you leave them.
All project content written and produced by Mike Edwards