Oxygenators are submerged, fast-growing plants that help to clean and oxygenate the water. They are essential if you want to keep fish in your pool because in a sunny weather, submerged algae may turn a new pool completely green in a week or two after installation and suffocate the fish. Oxygenating plants will compete for the dissolved mineral salts on which algae thrive, starving the algae this way and clearing the water.
Deep-water plants are the type of plants that flourish in a depth range of 30-90 cm. Apart from their ornamental value, those plants are also helping to reduce the algae from the pool with their floating leaves that cut down the amount of light that reach the water. The largest group of this type of plants are the well-known water lilies.
Surface floaters are plants that float over water. They play the same role in a pool life like the deep-water plants, but is vital not to let them cover too much of the water surface because this will make the oxygenating plants suffer if there is not enough light.
Marginals are plants that grow in shallow water, 7-15 cm deep and are usually very attractive plants. In a wildlife pond they will provide cover for wildfowl and small creatures that come to visit your pond. There are some species from this category that also help to oxygenate the water.
Bog plants are plants that enjoy living in waterlogged soil and can withstand occasional flooding. Plants that grow in moist or wet soil but don’t tolerate waterlogged soils are not suitable for this type of planting.
Moisture-loving plants thrive in soils that contain extra moisture but are not waterlogged. There are many herbaceous perennials that will suit this type of planting. They all associate well with marginals plants that are growing around an informal pond where the growing conditions are ideal.