small pond

Iris will give structure,shape, height and insect life support. Also, for novelty, "Cuckoo Pint" is a beautiful plant for damp areas.
..and PS, dont feel any wrong in struggling to maintain your garden, you are not alone (it hurts me n'all) and remember, "a garden is there for you, not you there for it"

Lythrum salicaria, Lobelia 'Vedrariensis' and candelabra primulas for example the Harlow Carr hybrids, Astilbes and Aruncus dioicus.

Is the pond in the shade or sun or both?

thanks for your help guys, it is in mostly sun Andrearichter :o)

Try Rodgersias if you like large foliage, but something that won't be too big for a small pond like a gunnera. There is of course ligularia dentata desdemona which has beautiful foliage and deep yellow flowers.