Lots of our gardens have dark, dank corners that seem to defy our best horticultural efforts. In these situations, ferns - delightfully pest- and disease-resistant - are ideal plants, creating pleasing, bold shapes with their textured fronds.
Existing ferns can be carefully divided now while they are dormant and replanted with a little bonemeal. Never use artificial fertilisers or lime, or animal manure (unless it is so well-rotted that it crumbles like peat): are all far too rich for these primitive plants.
Most ferns require damp soil, but one that does well in dry ground is tough Dryopteris filix-mas, the native male fern - but water it well until it is established. Osmunda regalis, the royal fern, is readily available in garden centres, and given damp conditions will reach truly noble proportions.
And if you are lucky enough to have acid soil, then the big, leathery Blechnum will grow for you, remaining green all year round.