Why not build a wildlife pond? Nothing attracts wildlife to your garden like water. All over the country ponds, lakes and streams have been slowly disappearing from farmland. So domestic ponds and water features are becoming ever more important for our native insects, amphibians and mammals.
The sound of the birds chirping as they drink and bathe in the morning. Or the hum of a dragonfly on a hot summer day takes some beating.
Starting your wildlife pond
Once you have decided that you want a wildlife pond in your garden, the first thing to decide is where to put it. Ideally the pond should be situated in a sunny spot away from overhanging decidous trees. The sun will help your plants and in turn the wildlife thrive; avoiding the overhanging trees limits the amount of leaf litter that will blow into the water, reducing your maintenance.
Adding a pond into an existing flower bed is sometimes a great option, the insects and amphibians attracted by it will help to control the aphids and pests to your plants. Or your pond could border a lawn or path on one edge to provide easy access and viewing.
Try to include a spot that can have some fairly dense planting adjacent to the pond or very close by. This could hide small log piles, pipes or other structures to give refuge to emerging frogs, toads and insects.
Design your wildlife pond
Once you have chosen your location you need to mark it out. You could use a marker spray to draw your outline, or use your hosepipe or a long rope to create the shape. Regular shapes like rectangles or circles can be quite jarring when the pond is a wildlife pond, they should ideally be a natural freeform shape and blend into the garden.
If your hose keeps recoiling and doesn’t bend to the shapes you want it in, just fill it with hot water, it will make the hose softer and more pliable.
Aim to have a shelf around the edge of the pond at least 12 inches wide, but a wider shelf in places can give you more pondscaping options when it comes to planting. I like to have a flat shelf around 14 inches wide around most of the pond, but widening it to around 2 feet at one end into a natural inlet shape, as if it were a river running into a lake in miniature.
Digging your wildlife pond
You have chosen your spot, and the shape you want, now is the time to get your spade and start digging.
Don’t just dive in and randomly start from the middle. Instead dig straight down from the edge 10 inches, you are aiming to get a sharp 90° edge. Then dig your shelf out, keeping the bottom flat and the soil remaining undisturbed.
You may have read on other sites and in some books about building wildlife ponds, and creating them with gently sloping sides and a lovely smooth spoon-like bottom. Creating your pond this way will result in awful black liner being on show every time the water level drops by even 1cm. Doing it our way will avoid this unnatural edge being on show, keep reading.
Once you have dug your shelf, your pond will look like a moat around an island. It’s time to move inward, removing the island from the centre, Dig down now with a gentle slope, you do want to create a smooth spoon like bottom from the shelf down to around 3ft ideally, although 2ft will be ok as a minimum.
Use the soil you have dug to distribute around the garden, create some raised beds or even grade your lawn. You will soon be able to lose this excess soil in an average sized garden. Although you do need to keep a few barrow loads back to finish your pond later.
Lining the wildlife pond
Time to visit your aquatics centre. Any aquatics centre will be able to supply you with a pond liner and underlay, just be aware that they may try and sell you filters and fountains and all sorts of stuff you don’t need. You are going to buy a liner and underlay.
Historically butyl rubber liners have been the best, most durable and long lasting liners you could buy. But the modern multilayer PVC liners are now outperforming them, with a lifespan of 40+ years in some cases!
You may think that underlay is a waste of time, it is in reality quite important. It creates a barrier between any sharp stones or sticks in the ground and your pond liner. With the weight of the water pushing down on the liner, sharp stones can easily puncture it. Leaving you with a repair job.
Instead of buying a dedicated pond liner underlay you can use an old carpet or underlay from your house, or even a soft sand, such as builders sand patted into the hole like a inside out sandcastle at around 30mm thick if you have any laying around. If not buy some, its not that expensive.
Once you have lined your pond smooth out any folds or creases in it, these will be visible through the liner when it is full of water.
On a fairly still day take your liner and lay it over the hole, finding the correct position for it. Push the liner into the hole, taking in all of the shelf contours, and weight the edges with bricks or similar sized stones (never stand on the pond liner with your shoes on, always in just socks or bare feet).
Now its time to get some shorts on and take your shoes off. Get the hose in and start filling the pond once you are happy that your liner is in the right place, with enough spare to take in all of the curves of the shelf and leave at least 12inches of excess at the top.
Get into the pond as its filling and fold your corners and curves, pleating the liner to neaten it. As the water fills up the pressure will hold them in place, removing the need to silicone them in place.
Levelling up you wildlife pond
While the pond is filling trim around the edges, leaving 14-18 inches of excess liner. Keep the edges weighted with the stones.
No garden is dead level, so it’s inevitable that you will have some low points in your edges and these need to be addressed if the pond is to look natural.
Any areas where the water is overflowing, lift the excess liner and back fill some of the subsoil that you dug out, making sure it is well compacted. Do this with all areas of the pond until you have done them all and your pond is full to the brim without overflowing.
Finishing the wildlife pond installation
Now carefully shovel soil into the pond so that it sits on the shelf around the outside. You are aiming to create a slope from around 6 inches from the edge of the shelf out of the top of the pond covering the liner. The natural inlet feature i mentioned earlier with a deep shelf will create a very gentle slope, with really shallow water that tadpoles will love as they emerge in early summer.
You should now have a very muddy pool that looks like something a hippo would wallow in. The water will be brown and murky, but you won’t be able to see the liner at all.
Do not be tempted to use all of those lovely flat slates or interesting rockery stones, that you have been keeping for when you had a pond, around the edges. These can be a big problem to wildlife. Imagine a lovely hot summer’s day the tadpoles are now turning into frogs, the newts are fully developed and both species are starting to venture out of the pond. They crawl out of the water up the lovely flat slate that extends down to your pond like a mini slipway. The sun is high and has been beating down on the pond for several hours.
Planting your wildlife pond
Leave your pond until the water starts to clear, it could be a few hours or a couple of days, dependant on your soil type. Now take a trip to your garden centre and aquatics centre to buy your plants. Before you go check the aspect of your pond location, is it full sun all day, or partial sun, or shaded? While this wont really effect the pond plants greatly, it will effect the ones you plant around it. Also test the acidity of your soil, you can buy a test kit from your garden centre. It’s much better to test it now, than be disappointed when your plants dont do well or die because you chose the wrong ones.
Your pond plants fall into three basic types. Marginal plants that only like a few inches of water above their roots, plants which like to be deeper, like water lillies and then floating plants whose roots never sit in soil or silt, instead they get their nutrients from the water. A fourth category of plants that could be useful are bog plants, or those that like a waterlogged soil, but dont like to be submerged. These plants could populate the pond edges, out of the water, but right on the edge.
You should be aiming for a combination of these plants to create a natural looking pool, with plants around the edges, in the shallows and deeper in the water.
Floating plants are the simplest to plant, literally chuck them into the middle of the pond. Some nice ones to consider are Water Lettuce, Water Hyanciths and Frog Bit. And oxygenators like Hornwort, Water Moss and Crowfoot.
Marginals require a little more care to plant. They come either pot grown, or bare rooted. Pot grown plants can be simply placed on the 6 inches of shelf that is free from soil and then weighted down with a few small stones on top of the pot. Bare rooted plants are even easier. Simply place the rhizome in the water, so that it is resting on the soil slope and weight it down with a stone to keep it in contact with the soil. Some good UK native plants which attract wildlife are: Bog Bean, Horsetail, Arrowhead, Bog Arum Lilies, Cotton Grass, Burr Reed Creeping Jenny and Brook Lime. For a splash of colour consider Iris and Blue Pickerals.
Larger pot grown plants which can survive deeper such as lilies are a welcome feature to any pond. Simply lower the pot into the water at a suitable depth, often they will also need to be weighted down also. Lilies will require maintenance every year, so all lilies that we put in have a length of nylon cord tied to the pot, green or black preferably. This cord is the then anchored to a peg outside of the pond, this makes retrieving the plant easier for maintenance and winterising the lily.
When designing your planting, consider your heights, combine carefully them to give the effect you want.
Watching your pond change
Over the first few weeks of having your pond you will see it change quickly. Firstly your pond will clear from the brown muddy puddle. Then it will turn a horrible green, like a pool of nuclear waste, this is called an algae bloom. The algae, a tiny plant suspended in the water will thrive on the nitrogen compounds in the tap water which you used to fill the pond. This will clear on it’s own. Don’t be tempted to top up the pond or start doing water changes, you will only make it worse. It won’t take long for the algae to use up all of the spare nutrients in the water, and die off. This will leave your water clear. Then your plants will start to take off, water plants tend to develop quickly using the nitrogen in the water.
Fish in your wildlife pond
Your pond is a wildlife pond and not suitable for fish. I hear you say fish are wildlife, while yes this is true nature balances the fish’s habitat very carefully. The bodies of still water holding them are balanced to the number of fish within them. The larger the pool, the more fish. If this gets out of balance the nitrogen compounds increase, algae takes over and chokes the lake killing the fish. The Nitrogen increases because of the fish waste, which rots at the bottom of the pond releasing the nitrogen. This is the nitrogen cycle, which any good aquarist will explain to you.
If you want fish then build a goldfish pond or a koi pond. Ensure you have adequate filtration to keep the nitrogen in balance.
Maintaining your wildlife pond
Even a wildlife pond needs to be maintained, the creatures and plants all have their requirements.
Keep at least a third of the pond surface free from plants. Don’t be afraid to throw the waste ones on the compost heap. Always check them for the mini beasts in your pond first.
I have a bucket of pond water to hand when i do this. Swoosh the waste plants in it bit by bit. Then carefully return the water to the pond, so that you don’t disturb the water and stir up silt.
Late autumn you can prune your lily rhizomes back by one third.
Winter means more maintenance drop hardy lilies into the deepest part of the pond. Non-hardy lilies should be lifted from the pond. You can keep them covered in buckets in a cool frost free place like your shed for the winter. Clean out any leaves that have fallen in or debris that has blown in.
Give your plants a final haircut of the year. Periodically you can remove some of the silt that will build up in the deepest part of the pond. But this won’t require doing for several years. When you do this be aware that creatures will be living it in. So pick through the sludge very very carefully.
We hope this article helped and that you and the wildlife enjoy your pond. If you want a pond but need help to create one, then please get in touch with your ideas and we will be glad to quote you to create one for you.