Pond plants like normal garden plants do better if placed in the correct spot. The most common water garden plant is the marginal aquatic plant.

Marginal water garden plants such as Iris, and Arum Lily which like to stand in water up to about 15cm (6”). Some can grow quite tall and be blown over by the wind so you may have to weight the pot or crate down with stones.

Marginal water plants as the name implies are those that occupy the shallower areas around the pond. Most of these plants do not like to dry out. Marginal water garden plants are also able to be considered as bog plants - ie those plants happy to grow in wet mud.

The Marsh Marigold, Reed Mace, Pickerel, Water Buttons, Bog Primula are typical examples of marginal water plants.

Other categories of water garden plants differing from the marginal class can be broken up as follows: 

Oxygenators as a class of  water garden plants assist in keeping plant water clean and clear by absorbing nutrients. Potted oxygenators include Water Crowfoot, and Water Violet are typical water pond plants.

Deep water garden plants the best known of which is the water lily – most people spell it water lilly. Please forgive me if I skip between the lilly ponds and the lily ponds, the water lily and the water lilly.

Floating water garden plants with their hair-like roots that protrude into the water and need no soil at all. These plants certainly assist in keeping water clear since they absorb nutrients from the water and do a good job of oxygenating lilly ponds. Water Hyacynth, or the water soldier plant are examples of this type of water garden plants.