Building a Natural Pond
Nearly 70% of ponds have been lost from the UK countryside, meaning garden ponds are more important than ever for supporting Britain’s fragile ecosystems. Ponds support almost two-thirds of our native plant and animal species providing food, water, breeding grounds, habitats and shelter. Furthermore, a well-designed and positioned pond can significantly improve the aesthetics of your garden, whilst also providing you with an area of tranquillity and peace. In addition to this, wildlife ponds are also vital for teaching the younger generations about the importance of local plants and animals. Ponds make for stunning feature elements for year-round enjoyment whether you are sitting in your orangery or a bench outdoors.
Location and pond design
Locating your pond in partial shade cover helps reduce problems with algae. However, a pond with too much shade cover is not good for wildlife so make sure part of the pond is in full sun. When designing the shape of your pond, try to incorporate at least one side of the pond with a long, shallow slope as this allows for easy access for wildlife and fluctuates water levels creating suitable habitats for more species. Butyl liners are the easiest way to create a naturally shaped pond. A depth of 20-60cm varied across the pond will suit the majority of flora and fauna
Creating your wildlife pond
After settling on a proposed site and marking the pond out with rope and marker pegs, excavate a hole to about 30cm, sloping the sides outwards by about 20 degrees and level out the bottom. Vertical pond walls can be built using bricks or concrete blocks. If using a butyl liner, place the liner over the pond and weigh the sides down with bricks. Then, let the water you are using to fill the pond weigh down the liner smoothly into the pond, lifting the bricks occasionally to prevent stretching and creasing.
When choosing the plants for your wildlife pond, make sure to select native plants to the UK. Non-native and potentially invasive plants can spread quickly and be very disruptive and harmful to your pond and the wider environment, possibly out-competing native plants. Always take plants from other garden ponds or garden centres, never from the wild as this can disrupt fragile wild ecosystems and your risk introducing diseases to your pond. You must also make sure to include a variety of different types of plants as these bring a range of different qualities and benefits to your wildlife pond and its inhabitants. These include:
Floating plants: These are plants that sit on the water’s surface, without needing to be anchored or attached to any surface below. Aim to keep around 50% of the surface covered by these plants, as their presence reduces sunlight discouraging algae, however, too much surface cover and there will not be enough sunlight available for submerged plants and you risk deoxygenation of the pond. Popular floaters include the white-flowered ‘Frogbit’, the red-in-autumn Azolla Mexicana and the ‘Water soldier’
Waterlilies: Waterlilies grow from the pond bed, sending long stems to the pond surface which open up into lily pads. These pads generally flower from July to September. It is important to choose your lilies based on the depth of your pond. ‘Pygmaea helvola’ and ‘Lucidia’ are best suited for ponds shallower than 45cm deep. Lilies such as ‘Attraction’ and ‘Marliacea chromatella’ are better suited for deeper ponds.
Oxygenators: Oxygenators are submerged plants that produce oxygen during the day and provide cover for aquatic life, playing a vital role in maintaining a wildlife ponds ecosystem. The free-floating ‘Hornwort’ is suitable for deep ponds, ‘Water crowfoot’ possess beautiful white flowers in May and ‘Water violet’ flowers with lilac in summer.
Marginals: These plants are ornamental in flower and foliage, softening up the outline of the pond. They also cast shade over the pond, playing an equally important role to floaters. Marginals such as ‘Sweet flag’ and ‘Marsh marigold’ grow in water shallower than 15cm, whilst ‘Great water plantain’ and ‘Arum lily’ amongst others will grow in deeper ponds.
Planting around your pond
The surroundings of your wildlife pond should be full and dense with plants to provide food and shelter to pond wildlife and act as a canopy for young amphibians leaving the pond. When choosing plants to grow, choose ones that grow well in moist soil such as those in the families Actaea and Astilbe, as well as shrubs such as Cornus alba and Weigela. Grow tall ornamental grasses such as Molinia (purple moor grass) and Miscanthus (zebra grass) to support life on the water’s edge. In addition to plants, you may want to consider adding a layer of gravel or large flat stones to the sloping side of your pond, as this is the perfect habitat for amphibians and insects and also provides safe drinking areas for birds and bees.
Water levels may drop throughout the hot months of summer due to evaporation, so remember to top up and keep water levels high. Use rainwater when possible, avoid using tap water as this contains high levels of nutrients which may cause nitrification. Weed and algae control is also important, particularly in summer when photosynthesis levels are highest. Keep algae levels to a minimum to avoid them covering too much of the surface and potentially killing oxygenators resulting in deoxygenation. Remove leaf litter in autumn for the same reasons. Sediment removal may be needed in autumn, but do this gradually to minimise the loss of mud dwellers. Cut back grass on the pond edge when it becomes overgrown to provide access to amphibians, except in winter to provide shelter for invertebrates.