Adding a water feature to your garden will bring so many different elements to your outdoor space – sound, movement, reflection and, of course, wildlife. Excavate and fill a pool, and you’ll be amazed how quickly it will be colonised by amphibians and aquatic insects. But then, to survive in the wild creatures need to be opportunistic, so don’t be surprised when they lock on to this promising area like a magnet.
Early spring is the ideal time to construct a pool because it will rapidly establish to offer wildlife an invaluable breeding ground. Water will warm quickly, allowing the life it contains to proliferate with ease. The design and construction of a wildlife pond is different to that of a more formal water feature. Here, we follow the process step by step, looking at these aspects individually.
Position your wildlife pond in a semi-shaded area, not full sun. The mix of stronger and weaker light will provide a diverse environment in which lots of wildlife can find its niche. Keep the hole away from tree roots, if possible, as these may pierce the liner as they grow (bamboo can be particularly troublesome in this respect). Mark out a kidney or similarly curved shape using a garden hose – this will provide ample space for creating shelves and slopes. Cut out the perimeter using a spade, then carefully lift the vegetation from the remainder of the hole (if digging in a lawn you can create a turf stack).
Begin creating different depths to your pool. Around some of the margins, create shelves upon which marginal aquatic plants can be positioned. You’ll also need a deeper central area. This can be useful for large plants such as waterlilies, and it will also ensure there is a cooler pocket of water in the centre of your pond. This offers diversity for wildlife and prevents the water heating up too quickly in the spring, which can lead to problems such as excessive algal growth.
While you can buy rigid, preformed pools it is easier and often cheaper to line your pool with a butyl liner which can be moulded to any shape. In either case, line the sides of your excavated pool with a 2-3cm layer of playsand. This will provide a cushioned base upon which your liner can sit. Dampen the sand slightly if it proves difficult to pack against any vertical sides.
Carefully lay your liner into the hole. When using butyl try to minimise creasing as you position your liner. Begin filling your pool with water – rainwater from butts is ideal but tap water is fine. As the water level rises carefully pleat the liner to create equally spaced folds, repeating the process until the pond is full. Don’t be tempted to trim the liner until the pool is fully topped up as it may constrict with excess weight. Then, using sharp scissors, cut off the surplus, leaving enough so that you can place paving slabs or other edging on top.
If room, you can also create a bog garden adjacent to your pond to further boost diversity. Excavate a 50cm deep hole, line it with butyl, pierce the base multiple times with a garden fork and then fill with an 8-10cm layer of pea gravel. Top this off with a 50:50 mixture of multipurpose compost and good garden soil. You can then plant up this bed with moisture-loving plants such as candelabra primulas, skunk cabbage (lysichiton), rheums and astilbes.
Adding extra features will improve the look of your pool and create more habitats for wildlife. Logs, whether in the water or alongside it, will quickly be colonised. Raised beds can be planted with moisture-loving plants, and cobbles and stone walls will be a favoured basking spot of reptiles. Creating a sloping edge of pebbles and gravel into the water will offer a transition area for aquatic life, a drinking and bathing area for birds, and an escape route for any land mammals misfortunate enough to fall into the water.
Once all the hard landscaping is complete you can begin planting up your wildlife pond. Choose native plants where possible, and those with single flowers – this will attract the widest range of creatures. A mixture of bog, marginal, floating and deep aquatic plants will also help here – specialist aquatic mail order nurseries are a godsend. Marginals such as miniature bulrushes, water mint and flag iris can be planted in mesh pots. Use aquatic compost which is rich in nutrients, and be sure to top off the pot with coarse gravel to keep it in place. Gently sink the pot onto your pool’s shelf and weigh it down with large cobbles. Unanchored plants such as water soldier and elodea can simply be placed into the water. Get a friend to help you lower plants such as bog bean and water hawthorn into deep water if you have created a large pool: thread a length of rope through the pot, and stand either side of the pool to lower it into position.
Adding a decking area will offer you the chance to sit by the pond and observe the creatures that it attracts – a well deserved reward for all that hard work! Fix it securely to the waterside using sunken vertical posts, and add some rustic seating that you and your aquatic companions can both enjoy.
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