The potato harvest last year was the worst for decades.

Tatties almost drowned in the cold, wet soil and were afflicted by every rot known to man. I can't gaze into a crystal ball, but I'll not be wasting time setting up an irrigation system this year. In fact, I'll be growing the crop differently.

The usual method is to plant potatoes in trenches to a spit's (spade's) depth. Pile the earth to one side, spread muck or compost along the bottom and lay the tubers on top. First Earlies are spaced 30cm apart, Second Earlies 40cm and main crop 45cm. The potatoes are covered with soil then you "earth up" – rake the soil from each side of the row to form a neat ridge along the planting line.

The tubers are planted deep for three reasons. First, if the growing potatoes are exposed to light, the skin becomes green, poisonous and unusable. Once the shaws, or growth, reach 10-15cm, earth up again to exclude light. Second, this method gives young plants some protection against late frosts. Third, a trench is a natural sump, gathering moisture from nearby ground. The challenge during a normal summer is keeping potatoes moist enough, so this trenching is worthwhile. Last year, it was disastrous.

So I'm trying another technique. After digging the ground over as normal, I'll spread a layer of homemade compost on top of the soil, along the row, then plant the tubers in holes just deep enough to cover them, using a trowel or dibber. I'll earth up as usual. This way, the soil shouldn't collect more water than any other part of the garden.

To prevent the potatoes being exposed to light, lay a 60cm biodegradable mulch along the row – straw or rough compost is ideal. The mulch must be at least 10cm deep, so a simple alternative is to cover the soil with a thick layer of newspaper. Hide this with compost or freshly mown grass clippings. Every time you cut the grass, empty the grassbox over your tatties. Make a hole in the paper at each planting station and don't let the grass touch the growing stems. This will give your spuds a fair chance. Be warned, though: mulches attract slugs, so you may need to protect the crop with a biological control such as Nemaslug.

Despite your efforts, you can't protect the crop completely and the huge leaf canopy needs the sunlight that was missing last year. John Marshall, a potato expert, advises gardeners to limit their planting. "Potato growing is fun," he says, "but a word of advice: keep it simple – grow the two or three varieties you like eating."

Last year's half-drowned potatoes faced yet another challenge. The cold, soggy soil encouraged rot in many forms. Over the past few years, bacterial conditions that thrive in such soil have been imported to the UK. Ring rot is a special horror and Dickeya solani, a bacterial malady, is a new threat to potato production in Europe. There are beasties too: the larvae of the flea beetle, epitrix, is making its journey north from Spain and Portugal, causing damage by burrowing into potato skins.

The Potato Council recently took steps to help control these problems. In 2003, the Safe Haven certification scheme was set up and most growers have signed up to it. Potato seed is tracked from production to sale, with soil and machinery tested for contamination. Imported seed, say from the Netherlands, may be contaminated, so it can't be grown next to safe Scottish seed.

You can avoid bringing any of these diseases into the garden by buying certified seed that enjoys Safe Haven protection. You're asking for trouble if you plant ware (eating) rather than seed potatoes because your soil could be contaminated for many years.

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