carrust, this is a quote from a Gardening Site
1.Avoid planting potatoes into heavy soil, which is favoured by slugs.
2. Avoid sowing potatoes into a site bordering grass, compost heaps or piles of organic waste, as all of these provide a base from which the slugs will carry out their midnight raids.
3. Dig over your soil once or twice before planting, this will bring slug eggs to the surface to be eaten by birds.
4. You can try planting potato varieties offering high resistance to slug attack such as Pentland Dell, or medium resistance such as King Edwards or Records.
5. Better still plant a variety that you can harvest early to prevent prolonged attack.
6. Avoid excessive watering of your crop, slug’s love slithering on wet soil.
7. Turn old wet sacks and rotten boards to your advantage, by leaving them encircling your potato crop. Arrive each morning with a smile, a wheelbarrow and a spade to gleefully scrape off the slugs from beneath these damp covers