Please do go for native plants and avoid the invasive alien ones which can take over ponds.
Don't put these in:
Curly Waterweed Lagarosiphon major
False-acacia Robinia pseudoacacia
Fanwort Cabomba caroliniana
Few-flowered Leek Allium paradoxum
Floating Pennywort Hydrocotyle ranunculoides
Giant Salvinia Salvinia molesta
Hottentot Fig Carpobrotus edulis
New Zealand Pigmyweed (Australian Swamp Stonecrop) Crassula helmsii
Parrot's-feather Myriophyllum aquaticum
Shallon Gaultheria shallon
Water Fern Azolla filliculoides
Water Hyacinth Eichhornia crassipes
Water Lettuce Pistia stratiotes
On this pdf link, the blue pages are the good plants and the white pages are the bad plants
http://www.plantlife.org.uk/uk/asset...tland-2006.pdf
and
CWT, Invasive Alien Pond Plants
If you put your postcode in the Postcode plants website
The Postcode Plants Database - Natural History Museum it will give you a list of what will suit your are. It includes marsh plants and water plants.
Forducks, Plant deep and plant alot and be prepared for muddy water and alot of churning up.
Good plants:
The following plants can act as native alternatives to non-native pond plants. These must never be collected from the wild and should only be bought from reputable garden centres, where their origin as cultivated plants can be assured.
Callitriche stagnalis Starwort
Ceratophyllum demersum Hornwort
Eleocharis acicularis Hair Grass
Fontinalis antipyretica Willow Moss
Hippuris vulgaris Marestail
Hottonia palustris Water Violet
Myriophyllum spicatum Water Milfoil
Myriophyllum verticillatum Whorled Milfoil
Potamogeton crispus Curly Pondweed
Ranunculus aquatilis Water Crowfoot
Nymphaea alba White Water Lily (for large ponds only)
Nuphar lutea Yellow Water Lily (for large ponds only