Potatoes have long been an allotment staple and, thanks to the grow-your-own boom, new gardeners are discovering the joys of tasting a freshly dug up crop. With a range of purpose-built tubs and bags now on the market, even those with only a patio or balcony can enjoy a foray into home growing.

In Britain around 450 varieties are available to the amateur grower, including heritage varieties, compared to the 80 or so grown commercially. The most popular for gardens are Charlotte, Desiree, Estima, King Edward, Marfona, Maris Peer, Maris Piper, Nadine and Romano.

Potatoes are categorised by their growing season. New potatoes or earlies are planted between January and March and harvested between May and July. Second earlies are planted between February and May and harvested from July to October. Maincrop potatoes are planted between March and May and harvested during September and October, when their skins are firm and set.

Potatoes are also grouped by their texture, which can range from waxy to floury, and this affects how they are best cooked. Other selling points are taste, skin colour and pestand disease-resistance.

Blight of both foliage and tubers is still a major problem affecting potatoes, but many varieties have resistance bred into them. One successful introduction in the last decade was Sarpo Mira. Another is the white maincrop variety Orla, which is said to have even greater resistance to foliar blight.

Other threats to watch out for are nematodes (also referred to as potato cyst nematodes or PCN), common scab, blackleg, mild mosaic disease and slugs.

A promising development in modern potato breeding is the use of mini-tuber technology to clean up varieties or resurrect heritage varieties. Scottish grower JBA Seed Potatoes has already achieved this with the varieties NVS Amour and NVS Sherine, which the company will exclusively make available next year as high-quality seed potatoes.

The process involves growing stem cuttings hydroponically in a sterile lab, yielding 100 per cent disease-free plants. These then produce tiny mini-tubers, which are then grown in the soil to produce seed potatoes the next year. It is said that the seed potatoes can be replanted for around 10 generations.

All varieties are sold as individual tubers at the start of the season. Gardeners usually "chit" them — allow them to sprout in the open — before planting, to promote establishment. They are then earthed up to cover the stem bases with soil. When harvesting, care should be taken not to leave tubers in the ground, as this can cause disease.

WHAT THE SPECIALISTS SAY

Dr Mark Fletcher, head of horticulture, Unwins "We do about 40 varieties for the retail market, including first and second earlies, maincrop, lates and salad potatoes. We also offer organic potatoes including Robinta — a red-skinned maincrop type — and Orla, both of which have been bred to have high resistance against blight.

"We also offer Have A Grow packs of 10 small tubers. Orla is one of the potatoes available in these packs, alongside our other new varieties, maincrop potato Elgar and First Early Annabel.

"Having said that, the traditional favourites are still the most popular the garden centre — varieties such as Maris Piper, Pentland Javelin and Homeguards. Any new variety has to add something — either a different look or disease resistance. Anything to help the gardener — they don't want to have to spray if they can help it."

Robert Barbour, managing director, Jamieson Brothers Annan Seed Potatoes, Dumfriesshire "The older varieties are still very popular, such as the first earlies Duke of York and Red Duke of York — nice floury potatoes that chip well. The maincrop King Edward is still highly sought after too.

"We also offer heritage varieties such as Gladstone, which is a particularly good all-round potato, as is Pentland Lustre. We have two purple-skinned heritage varieties — Edgecoat Purple and Ryecroft Purple. We even have a very old variety called Shetland Black, which when cut in half reveals surprising blue and white rings.

"We have two varieties of mini-tubers exclusive to us — NVS Amour, a round, white potato with pink eyes; and NVS Sherine. With this technology it would be possible for our company to grow a special old variety for a garden centre group that would be unique.

"The biggest problem when growing potatoes is blight. There is the potential that some fungicides to protect potatoes will be banned under the new EU regulations, but there should still be a sufficient list of approved chemicals."

IN PRACTICE

Richard Stevenson, sales director, Charlton Park Garden Centre, Oxfordshire "We are a garden centre but we've also been offering seed potatoes by mail order for five years. We find both ways of buying are popular. We sell the same tonnage of seed potatoes online as we do in the centre.

"Our hot sellers are Vale's Emerald', a Charlotte cross, and the maincrop variety Argos — perhaps because of its drought resistance. We buy most of our potatoes from Scotland — they grow the older varieties — and we get a few of the newer varieties from France and Holland.

"We hold a seed potato weekend every January in Whitchurch. It's our 13th year running it and it offers our customers the opportunity to see around 150 varieties of potato, swap seeds, attend a lecture and see cookery demonstrations. We usually get around 2,000 visitors through the door."

SPECIES AND CULTIVARS

Accord has bright uniform oval tubers with white skins and flesh. It is an early variety that produces high yields but cannot be stored for long. Good resistance to common and powdery scab. Very waxy and good for wedges.

Anya is a second early with a long, thin, white body and a nutty taste and waxy texture that make it a popular salad potato. It produces high tuber numbers and has good overall disease resistance but is susceptible to damage and greening.

Cara is a maincrop variety with white skin and distinctive pink eyes. It is robust and has excellent resistance to drought, foliage and tuber blight as well as common scab and viruses. Extremely high-yielding and uniform, and recommended for jacket potatoes and chips.

Charlotte is a long, oval, white potato with a moist texture. It is a second early, highly resistant to foliage and tuber blight but susceptible to potato cyst nematode. Usually marketed as a salad potato, it is also good sauteed and as a firm roast potato.

Desiree is a maincrop variety with red skin and light yellow flesh. It has high resistance to drought and good resistance to potato virus Y and powdery scab. It can be boiled, roasted, baked, mashed or chipped.

Edgecote Purple is a purple-skinned heritage variety, first listed in 1916. It is a long, oval, yellow-fleshed variety with a firm waxy texture and is a good all-rounder. Has shown high blight resistance when tested under organic conditions.

Gladstone, first listed in 1930, is an oval, creamy-fleshed potato with a floury texture. Still shows good resistance to scab and blight.

Harmony is a smooth, rounded maincrop variety with very pale white skin and flesh. It stores well and is recommended for boiling.

Maris Piper is the most popular variety grown in the UK and is widely used in fish and chip shops because it is so reliable. It has creamy white skin and flesh and a floury texture. It is resistant to potato cyst nematode but moderately susceptible to common scab, powdery scab, potato virus Y and slugs.

NVS Amour is a round, white potato with pink eyes, considered so uniform it is often used as a show potato.

Orla is an early maincrop potato with smooth, creamy skin, light-yellow flesh and excellent taste. It also produces high yields, shows good foliage blight resistance and excellent tuber blight resistance. It is suitable for organic production.

Pentland Javelin is a first early variety with white skin and flesh. It is soft with a waxy texture and good for salads.

Sarpo Mira is an excellent all-rounder. Bred to have the highest blight resistance, it also produces high yields of floury tubers. It is a late maincrop variety. Grows in a range of soil types and has vigorous weed suppressing foliage. Organic and non-organic are available.

Sarpo Axona was bred to have similar blight resistance to Sarpo Mira, but with more regularly shaped tubers.

Vale's Emerald produces masses of round, cream-skinned tubers that are excellent in salads. A first early variety, the result of crossing Maris Peer with Charlotte.

Vivaldi is a sought-after variety because it can be harvested young and as a second early or early maincrop, and it has good common scab resistance. It has creamy skin with light-yellow flesh and is considered one of the best-tasting potatoes.