There are many so-called 'marginal plants' which can be grown in pots at the edge of the pond with the crown of the plant barely submerged - if they're put in too deep, they won't flower.

Typical marginal plants include: Caltha palustris (Marsh marigold); Iris sibirica; Iris versicolor (the American flag iris); Iris ensata (previously called kaempferi) and Iris laevigata, the Japanese irises.

The miniature bullrush, Typha minima, is suitable for the smallest of ponds - even a tiny tub - and variegated leaves are found on a number of plants including Scirpus tabernaemontani zebrinus and Glyceria manicata variegata.