Damp shade in a garden is easier to accommodate than dry shade and there are a good number of plants which will tolerate and be happy in damp areas with reduced sun. The combination illustrated include Iris, Carex, Astilbe, Hosta and cotton grass all of which are happy alongside and in the margins of a pond.
Hostas much prefer growing in shade and in these conditions produce the best leaf colour. There are over 70+ species of Hosta too numerous to list, but there is one for every garden, big or small, plain leaved, variegated yellow or silver, blue leaved Hosta and also lime greens. The only drawback and problem are the garden's number 1 enemy: slugs and snails love Hosta as much as we do. Before you plant tips on how to beat the slugs.
There are even more Irises in the world than Hosta. Iris are divided into groups and the Laevigatae group are known as water Irises which thrive in damp places as do Louisiana Irises; check the label on purchase. This group include the blue iris illustrated and the yellow flag Iris which is very attractive but a bit of a thug, ideal if you have a long bank to cover.
Carex elata 'Aurea' Bowles golden sedge is a well behaved bright green sedge which will grow both in moist soil and in water and has a lovely arching shape.
Planted in the above but not quite visible is one of the Astilbe group, a herbaceous medium sized plant which is very happy in damp and even boggy sites with feathery plumes of flowers usually either white, pink , mauve, red and yellow. It is very easy to grow and comes up reliably each year flowering from mid summer onward.
More ideas on plants for damp shade