Growing potatoes

What to grow

• There are dozens of different potato varieties, usually described as early, second early and maincrop potatoes.These names indicate when they crop and also give you an idea of the space you'll need, how closely and when they can be planted.
• You should concentrate on the earlier types if you're short of space, and it's also worth remembering that earlies are less likely to encounter pest problems as they're lifted so much earlier in the year.
• Second earlies take 16 to 17 weeks to mature after planting, so you should be able to harvest them from very late June through to the start of August.
• Maincrops are ready 18 to 20 weeks after planting, so they can be lifted usually from July through to October. Maincrops take up the most space in the garden, but they tend to be the best varieties to grow if you want some for storage.

What to do

How to chit

• Chitting simply means encouraging the seed potatoes to sprout before planting.
• Start chitting from late January in warmer parts of the country or in February in cooler areas, about six weeks before you intend to plant out the potatoes.
• Each seed potato has a more rounded, blunt end that has a number of 'eyes'.
• Stand the tubers with the blunt end uppermost in trays or old egg boxes, with plenty of natural light.
• The potatoes are ready to be planted out when the shoots are 1.5-2.5cm (0.5-1in) long.

How to plant

• Plant your chitted potatoes when the soil has started to warm up, usually from mid-March or early April. Start by digging a trench 7.5-13cm (3-5in) deep, although the exact depth should vary according to the variety of potato you're planting.
• Add a light sprinkling of fertiliser to your trench before you begin planting.
• Plant early potatoes about 30cm (12in) apart with 40-50cm (16-20in) between the rows, and second earlies and maincrops about 38cm (15in) apart with 75cm (30in) between the rows.
• Handle your chitted tubers with care, gently setting them into the trench with the shoots pointing upwards, being careful not to break the shoots. Cover the potatoes lightly with soil.
• As soon as the shoots appear, earth up each plant by covering it with a ridge of soil so that the shoots are just buried.
• You need to do this at regular intervals and by the end of the season each plant will have a small mound around it about 15cm (6in) high.

Harvesting

• Your home-grown potatoes should be ready for lifting from June until September, depending on the varieties and the growing conditions. Earlies can be lifted and eaten as soon as they're ready.
• This will be when above-ground growth is still green, and usually as soon as the flowers open.
• Second and maincrop varieties can be kept in the ground much longer, until September, even though above-ground growth may well be looking past its best.
• Two weeks before you lift the crop, cut the growth off at ground level. This should give the skins of the potatoes sufficient time to toughen up, making them far less prone to damage from lifting and easier to store.

  Growing tips

  • Potatoes like plenty of sun, so avoid planting them in frost-prone sites, as these conditions can damage the developing foliage. If you're starting up a vegetable plot on very weedy ground or old grassland, potatoes may help swamp out weeds with their fast-growing, extensive foliage.
  • If you're short of space, try growing potatoes in an adequately drained container that's at least 30cm (1ft) deep and wide. Half fill the pot with multi-purpose compost or good quality, fertile garden soil, nestle two seed potatoes into the top of the compost and then top up with more compost or soil to within 2.5cm (1in) of the rim of the container.
  • It's particularly important that there's adequate water once the tubers have reached the size of marbles. Unless there's regular, ample rainfall, the size and quality of the crop will be reduced if you don't water your potatoes.