How to grow potatoes
The staple ingredient of many a meal, potatoes are a popular and versatile crop that have so much more taste and variety than the standard varieties available in the shops.
Potatoes traditionally take up a lot of room on the plot but it is possible to grow your own potatoes successfully in containers too. Although yield won't be huge, concentrate on growing the delicious, more unusual new potatoes that are either unavailable or expensive in the shops - and these are usually harvested early too, which means you should avoid the frustrating disappointment of blight. When considering how to grow potatoes out of the ground, the secret is depth - so choose your container carefully. Purpose built bags are available, or try large, deep pots, even old plastic dustbins.
How to grow potatoes
A good tip before you even start thinking about how to grow potatoes is to chit them first. This means helping them to sprout before planting by standing them in egg boxes or trays in a cool, light place. Put the end with the most eyes upwards and leave them to shoot. When the shoots are around 2.5cm long they can be planted out in a sunny, frost free spot.
Read our guide on how to chit your potatoes.
The best time to sow seed potatoes depends on the type - around late March for earlies, early to mid April for second earlies and the end of April for maincrop varieties. Another helpful tip on how to grow potatoes is that it is important to keep light away from the developing tubers; potatoes are best grown either in trenches and earthed up, covered with soil as they grow, or under black plastic - this has the advantage of needing no earthing up or digging as tubers are produced just below the surface.
If growing potatoes in pots or bags, plant them on about 10cm of soil at the bottom of the pot and add compost up the stem as it grows until the pot is full. But however you grow your own potatoes, water plants well in dry weather and give them a general liquid feed every couple of weeks.
The biggest problem when growing your own potatoes is blight, a fungal disease that can wipe out an entire crop. Common in warm, wet weather it usually strikes around late summer, so the best way to avoid it is to grow early varieties, which should be out of the ground before it hits. Otherwise, look out for the distinctive chocolate blotching of leaves and stems and cut them down to the ground immediately to stop the blight spreading to the tubers below. Leave the potatoes in the ground for a couple of weeks for their skins to harden and hope you have a crop left.
When to harvest potatoes
It can be tricky to know when to harvest potatoes as all those lovely tubers lie unseen below the ground, and it does depend on which type you are growing. Early potatoes are ready to harvest when their flowers open, around June and July - just have a careful feel around in the soil for the tubers. They are ready when they are about the same size as an egg and best eaten straight away, so only lift them when you need them.
You can tell when to harvest maincrop potato varieties however, when the foliage has turned yellow. Cut it down and leave the potatoes where they are for a week or so to help their skins harden and then lift, allowing them to dry in the sun for a few hours. These can then be stored in breathable bags such as jute, somewhere cool and dark, like a shed or garage.