IF YOU think potato varieties only stretch to floury or waxy, then how about trying the yellow flesh of a long oval Wilja potato, or Edzell Blue, with its blue and purple skin?

Supermarkets offer more varieties of potato than they used to – but the best way to get hold of some unusual ones is by growing your own.

In fact growing potatoes, along with the whole grow-your-own movement, seems to be enjoying a renaissance.

When Nottingham Organic Gardeners held their Potato Day in Sherwood recently, it was so popular that people were queuing out of the door before it started.

The group had 48 different varieties of seed potatoes for sale, getting through literally thousands of tubers by the end of the day as hundreds passed through the doors of Sherwood Methodist Church Hall.

"I think it was the third potato day we've held," said Karen Fry from Nottingham Organic Gardeners. She said the event helped raise money for the group and gave people the chance to buy lots of different varieties in small quantities; they also got advice on growing.

Karen helps out at the Nottingham Organic Gardeners' plot on Whitemoor Allotments but doesn't have her own plot; she grows potatoes in a compost bag in her back garden.

Karen uses an empty bag and fills it with about 10cm of compost to plant the seed potatoes in; it is then gradually topped up with more compost as the potatoes grow, as a substitute for the "earthing up" which needs to be done when potatoes are grown in the ground.

Earthing up involves drawing soil around the stems of plant, and is essential to prevent tubers from turning green and poisonous.

The need for "chitting" potatoes prior to planting is open to debate, however. Once said to be vital for growing healthy potatoes, it involves setting seed potatoes in egg boxes or wooden trays in a light, frost-free room until they produce shoots.

Now many gardeners say that chitting is not necessary – including potato expert Alan Romans, who has written several books on the potato.

The varieties which sold well on Potato Day give an interesting indication of public taste.

First to sell out was Desiree, a pink-skinned variety with yellow flesh. Suitable for roasting, boiling and baking, it is said to have an excellent flavour.

Second favourite was Lady Balfour, a high-yielding organic variety with excellent resistance to blight. Third was the King Edward, renowned for its light fluffy texture.

"Some people have got their favourites. The Charlottes always go really quickly," said Karen. "Some people want to try something different. We always get people coming along who say, Oh goodness, I didn't know there were so many!"

There was a craze for different varieties a hundred years ago.

"There was a Scottish potato bubble from 1900 to 1904," said Karen. "People would produce a new type of potato and assume they would get lots of money from it and invest in it – and it collapsed around them, just like the dot com bubble did."

Modern-day potato growing has become quite competitive. Karen said some allotment-holders will do their best to grow the earliest potatoes by warming the soil with black polythene. Some enthusiasts are growing from actual seeds, rather than seed potatoes. The seeds are contained in tiny fruits which emerge from the flowers of mature potato plants, and resemble little tomatoes.

Tomatoes and potatoes are both in the nightshade family of plants. As well as both being susceptible to blight, parts of the plants are poisonous. This meant people were initially wary of eating potatoes when they were introduced here.

The botanist Olaus Rudbeck recommended them as garden flowers. "He said potatoes are equally as suitable for the flower bed as the table," said Karen.