The Zones

A pond is divided into 5 planting zones, all of which depend on the depth of your pond, although there is some natural overlapping.

  • Zone 1 contains the marginal plants.
  • Zone 2 contains the marsh or bog plants varying in depths between 0 and 15 cm under water.
  • Zone 3 contains the water plants that have to be planted between 0 and 40 cm under water.
  • Zones 4 and 5 contain the water lilies and oxygenators at various depths between 40 and 120 cm under water.
  • Zone 6 contains the surface floaters that float on the surface of the pond.

When you buy plants they will normally come with a label showing you the best location for the plant in your pond.

Marginal plants
These plants stand around the pond in straightforward garden soil. The soil is dry to moist and can become waterlogged as the result of heavy rain or if the pond floods. Marginal plants should be chosen for their shape and height to create a gradual transition to the actual water plants. Another way of creating an attractive transition from garden to pond is by using a layer of pebbles or stones that continues into the edge of the pond. Pebbles and rocks can also be used to camouflage the edges of a pond liner or of the preformed mould. Plants can be planted among the stones and pebbles to look as though they are growing into the water. The result is very natural looking.

Marsh or bog plants
The marsh area starts immediately over the edge of the pond. This area is freely accessible to the pond water, which will keep it wet. Marsh plants need their roots to be between 0 and about 15 cm under water, depending on species. The labels of these plants always indicate what depth of water they can tolerate. It is very important to maintain your marsh plants carefully to ensure they do not become messy and untidy. One way to inhibit the more invasive varieties is by planting them in pond baskets.

Water plants
Heading into the pond from the marsh or bog zone, we arrive at the water plant zone. These are the plants most suitable for planting in the deeper parts of the pond and must have their roots under water. In fact they can grow completely under water, to a depth of up to 40 cm. Here again you can use pond baskets for planting. The baskets should be filled with aquatic compost for deep water plants or substrate and covered with gravel.

Water lilies
Finally we reach the pond’s deep water zone, which is a suitable habitat for plants such as water lilies. Water lilies take root in the soil at the bottom of the pond and prefer calm, stagnant water. Water lilies create areas of shade under their leaves and this inhibits the growth of algae. During the day water lilies are a delight to the eye but they close their flowers at night and when the weather is gloomy. The depth at which the different varieties of water lilies should be planted is shown on the label accompanying the plant. It can vary between 40 and 120 cm deep. This means that there is a water lily for every type of pond. Water lilies are generally planted in baskets and then placed on the bottom of the pond, container, trough or tub.

Oxygenators
Like water lilies oxygenating plants belong in the deeper regions of the pond. Oxygenating plants remove large volumes of nutrients from the water and compete for the dissolved mineral salts on which algae thrive, thereby starving the algae out. The purpose of oxygenators is to produce oxygen, some of which is absorbed by the water. The oxygenated water is more efficient in terms of promoting the natural breakdown of waste materials in the pond water. This prevents rotting in the bottom layers of the pond bed. Oxygenators are available in pots and in loose bunches. The bunches can be planted in baskets filled with aquatic compost or substrate and covered with gravel. 5 bunches per cubic metre is the recommended quantity.

Surface floaters
These plants simply float on the surface of the pond. They are not planted, but are laid in the water. They produce roots to absorb nutrients from the water, rather than to attach themselves to anything. Surface floaters are an important element of a healthy pond. They filter the effects of sunlight on the water and remove large quantities of mineral salts. This inhibits the growth of algae. Surface floaters multiply at speed and it is essential to remove plants from the pond regularly to stop the surface from becoming completely covered. We recommend always keeping two thirds of the water surface of your pond free of plant cover.

Pond layout