Several hundred potato varieties are grown in Scotland and elsewhere in northern Europe.

As an illustration, Ian Barbour of JBA Seed Potatoes in Annan entered the Guinness Book of Records by exhibiting almost 670 varieties at last year's Gardening Scotland. On a lesser scale, potato days may tempt you with more than 100 varieties and the better mail order firms will supply up to half that amount. Small wonder folk don't know where to start.

I've often come back from a potato day with twice the tubers I've space for. So, the first golden rule is: work out how many potatoes you can fit in. You may only have room for two or three growbags on the patio. The general advice is to plant three, five or seven tubers to a bag but you'll get the same weight of potatoes, regardless of the number you plant. So, to avoid pea-sized tatties, never plant more than three. I find one per bag produces a good crop of decent-sized spuds.

It's easy calculating numbers for a row in the vegetable garden. Each bed should be one metre wide because you'll need a lot of soil for earthing up - making a deep ridge of soil to cover the growing potatoes. Space First Earlies 30cm apart; Second Earlies, 38cm; and Maincrop 45cm.

Very few people have room to grow their annual supply of potatoes; you'd need a traditional kitchen garden for that. In fairness, supermarkets offer a much better choice than they did a few years ago, so concentrate on spuds that are best when freshly dug or not stocked in supermarkets.

You can harvest quick-growing First Earlies after 10-12 weeks and you can cram in more potatoes than the slower-growing Second Earlies or Maincrops. Nothing beats adding the first tubers of the year to a basket laden with a crisp lettuce and succulent peas.

Ca' canny, though. Taste is paramount and flavour varies hugely between varieties. Taste is personal, so forgive me for mentioning some that do or don't suit my palate. Swift and Rocket put their energies into speedy growth rather than flavour - I couldn't tell what I was eating on a blindfold test. This goes for the likes of Lady Cristl and Accent too. On the other hand, Red Duke of York and Ulster Sceptre are worth all the space you have.

If you can fit in more than First Earlies, choose ones that mature before late potato blight strikes. This airborne fungal disease thrives in mild, humid conditions and will devastate a crop in days. There are varieties, such as Cara and Lady Balfour, with some blight resistance and, as I've said before, the Sarpo group is impregnable.

Second Earlies mature in 12-14 weeks, so provided you plant them at the same time as your First Earlies you'll beat the blight. Luckily, there are much tastier tatties than the dull Lady Balfour. For a waxy salad spud I can't see beyond Nicola, with Charlotte a good second. And Marfona is in an altogether different league to Cara if you want a baker. Tasty bakers are hard to track down, so I always have a bag of Marfonas in the shed.

Top of my list of Second Earlies is Mayan Gold. Almost uniquely, this potato is not a Solanum tuberosum variety, but one of the sub species, Solanum phureja. The Scottish Crop Research Institute has been working on this new group over the past 20-30 years and launched Mayan Gold a few years ago. Mayan Gold, Mayan Princess, Mayan Queen and Mayan Twinkle are probably the tastiest tatties you'll come across. They're unquestionably the best roasters ever. Cylindrical and not very large, they're easy to scrub, cut in half lengthways and roast.

Some old favourites - including Pink Fir Apple and Highland Burgundy Red - are late Maincrops and susceptible to blight, so I've given up on them. Back the winners, I say.