Potatoes are a member of the solanaceae family, shared also with tomatoes and aubergines. They vary widely in variety, texture and size and are easily grown in the ground or suitable sized container on your patio. We all have our favourite potato recipes and these vegetables are very versatile in cooking; absorbing flavours and holding their shape well. They are a useful addition to any kitchen and can be prepared in many ways; mashed, boiled, baked, roasted, deep-fried, sautéed.
Potatoes are grouped in categories according to how long they take to mature.
First Earlies – Plant late February – 10 weeks to maturity – ready between June & July
Second Earlies – Plant early March – 13 weeks to maturity – ready between July & August
Early Maincrop – Plant early March – 15 weeks to maturity – ready around August
Late Maincrop – Plant early March – 20 weeks to maturity – ready around September
Growing in the ground
Potatoes are grown using certified seed potatoes that can be purchased around January onwards. Although some people will plant supermarket potatoes that have sprouted, there is no guarantee that the crop will be free from disease. Special seed potatoes, sold by plant merchants and garden nurseries, are used to help prevent disease.
When you receive your tubers, you will need to chit them. Chitting potatoes simply means getting them off to a good start by placing the seed potato rose end up (the blunt end with the most shoots or ‘eyes’) in an egg tray or seed tray. This tray is then positioned in a frost free, light place to encourage them to produce strong, stubby shoots. This process is more important when planting early varieties of potato.
To plant potatoes in the ground, prepare drills in the soil and place a well chitted tuber in the base of the drill, shoots facing upwards. Follow the spacing guidelines as shown below for each type of seed potato. Return the soil , gently over the tubers, trying not to damage the sprouts. When the first shoots of the foliage appear, continue to draw up the soil around the leaves every two weeks or so until each potato plant is on a large mound of earth.
First Earlies and Second Earlies: 12in/30cm apart and 4in/10cm deep in rows 18in/45 cm apart.
Maincrop varieties: 15in/40cm apart and 4in/10cm deep in rows 24in/60 cm apart.
Growing in containers
Potatoes take up a lot of space in the ground but they can be successfully grown in large pots, bags or containers. The minimum space needed is a growing container of 30cm or more. You can purchase specially designed bags that will give you successful results but you could use recycled compost bags, large sacks, containers or as I have done old dustbins and plastic water tanks!
Start them off in a frost free place, like a greenhouse in mid February. Simply space out 2 or 3 chitted seed potatoes, depending on the size of container you are using, in the base of the pot that has at least 30cm of compost. Add a small sprinkling of general fertiliser, or potato fertiliser, cover the tubers with at least 10-15 cm of soil and continue to earth up as the foliage appears. Keep the compost moist but not overly wet.
Pests, problems and Diseases
Avoid exposing the potato tubers to light. Green tubers are inedible and poisonous but these can easily be prevented by covering the tubers with the surrounding soil. This process is called ‘earthing up’
The potato foliage may produce flowers, that when pollinated, produce small green fruit that resembles tomatoes.. These are highly poisonous and are related to deadly nightshade!
Potato Blight, a devastating fungal disease, is rife during wet and warm summers and can be a big problem. Symptoms include yellow or brown patches on the leaves and stems, followed by the plant completely dying off and the spores spreading down to the tubers, which then rot. There are a few varieties of potatoes that are blight resistant such as Blue Danube, Sarpo Mira and Kifili. Any infected crops need to be disposed of throughly, preferably burned to reduce the fungal spores from spreading.
Powdery scab, another fungal disease, may also affect your crop. The symptoms of which are raised scabs that burst into powdery masses of spores.
First Early – Arran Pilot, Pentland Javelin, Home Guard, Swift, Red Duke of York
Second Early – Charlotte, Estima, Picasso, Kestrel
Main crop – King Edward, Maris Piper, Yukon Gold, Nicola