English Nature - Garden Ponds And Boggy Areas - Havens For Wildlife

Garden ponds and boggy areas: havens for wildlife

working today for nature tomorrow

Why have a garden pond? Most people are fascinated by water and a garden pond is an excellent way of having it close to home. Garden ponds provide beauty and interest, and if well designed, will make a real difference for wildlife. Ponds and biodiversity England is damp and cloudy, and naturally full of ponds, wetlands and the plants and animals they support. But the drive to intensify agriculture has hit hard. Land drainage, from the Romans onwards, reduced pond numbers to about 1,250,000 in 1890 and to only about 400,000 today. Most of these ponds were made for watering stock, or were used for foundries, mills or water storage. Many are now polluted from run-off from roads and agricultural fields. Others are changing naturally, through lack of management, and are overgrown by trees or filling with silt. While still important for many species of wildlife, they rarely contain an abundance of common species. Garden ponds help to reduce this loss. Few will sustain endangered or highly specialised species, but they can be a real haven for many others. Frogs may be doing better in suburban gardens than in the wider countryside. Well-designed garden ponds can provide a refuge for many species of freshwater plants and animals. They are valuable for other wildlife too. Birds drink and bathe in

Top: Frog with reflection. Andy Sands Bottom: Starling. Paul Keene Opposite: Ragged robin. Chris Gibson/English Nature

the shallow margins, or eat the autumn seed heads of reeds. Insects feed on exposed mud, and at night, bats hunt for flying insects over the water. If you want to see plenty of wildlife close to home, put in a garden pond. Garden ponds

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Formal ponds like this one are not built with nature in mind. Bob Gibbons

Ponds and garden beauty Ponds can look marvellous in gardens. Water gives a natural, peaceful effect. Reflections add brilliance, colour and movement. Having a pond – especially with a bog garden – allows a greater variety of plants to thrive, and even in the most scorching summer, ponds remain lush and refreshing to the eyes. The birds and insects they attract animate the summer garden, and there is joy and fascination in watching the changing occupants and character of the pond through the seasons. For older children, there can be few better introductions to the natural world than discovering the extraordinary wild creatures that lurk in and around garden ponds. 4

What is the purpose of your pond? This leaflet is about creating a pond for wildlife. Formal garden ponds, often concrete, with vertical sides and overhanging flagstone surrounds, can give a strong central design to a garden and are valued for reflections and shape. However, the steep sides make them dangerous traps for hedgehogs and mice. Even cats and dogs may fall in and be unable to climb out. Frogs and toads will be trapped in the pond, and may drown once past the tadpole stage. Many people want to keep fish in their pond. Unfortunately, they may

dig up bottom-rooted vegetation and most will eat tadpoles and other pond animals. If you regularly feed large numbers of fish, the nutrients added to the water will encourage green algae and blanket weed that can smother the whole pond in a very short time. Most ponds with large fish have to have pumps, filters and aerators. The answer may be to have one pond for fish, and another, without fish, for wildlife. Gardeners usually want to add exotic plants to their ponds, as to their flowerbeds. These will not stop plenty of interesting native animals colonising their ponds, but plants long-adapted to conditions here normally support a greater variety of invertebrates. Wildlife ponds should contain mainly native plants, many of them very beautiful.

Designing your pond Think carefully where your pond is to be. Once dug, it can’t be moved! If it’s in sight of the living room or kitchen windows, you’ll be able to watch birds, bats and other visitors from inside your home. If the pond is away from the house, it may attract more timid species, and you can plan the garden so the pond is a beautiful surprise in a private corner. Mark out the outline with canes and see how it will look before you start digging. Aim to have part of the pond in full sunlight. This allows the water to warm up quickly in the spring, so encouraging plant growth. Some wildlife species prefer shaded water, but avoid digging a new pond right by a large tree as you may damage

Even very small ponds can be rich in wildlife. Bob Gibbons

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the roots. Worse, new roots may penetrate your liner and your pond may fill with leaves. Think also about where the water supply is to come from. How big should it be? This is up to you and your budget. Bigger ponds mean more plant species and a more varied habitat for animals. But doubling the dimensions of a pond increases the liner cost four times, and creates eight times the volume of soil to dispose of! The pond should be in scale with the rest of your garden: even tiny ponds can hold a lot of wildlife. If you have the space, an excellent arrangement for wildlife is to have one larger pond, several shallow small pools and a bog garden area, allowing some pools to become muddy or dry in the summer. This variety of habitats will ensure a great diversity of species.

Green woodpecker. Chris Gomersall

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Garden ponds needn’t be deep. Most pond animals are found in the shallowest water – a couple of centimetres deep. Deep open water is the most dangerous habitat for small animals, especially if fish are present - so maximise the shallows. For a wildlife pond, 40-50cm is deep enough, and will mean much less soil to remove. A clean water supply is crucial. If water is contaminated with fertilising nutrients, you will face a continual struggle with algal build up. If your pond is on a slope, it will fill from rainwater run-off. It is, then, very important that the ground above the pond is not artificially fertilised, or left bare, because nutrients and silt will wash in.

The cuckooflower is one of the main food plants of the orange-tip butterfly. Chris Gibson/English Nature

Water boatman Corixa punctata. Bob Gibbons

Most people fill their ponds with tap water. This is easy – but rather wasteful. Tap water also often contains high quantities of nutrients that encourage algal growth. The best possible source is rain water. Can you site your pond close enough to the house or a greenhouse or shed, to be able to siphon water from a butt? With a little ingenuity, you may be able to divert water from a down-pipe directly into the pond. What shape should the pond be? Straight edges look unnatural and should be avoided. The margins are best for wildlife, so in larger ponds, try for a wavy-edged oval rather than a plain circular shape. The most important design element is the profile of the sides. Make sure you leave LOTS of shallow water shelf

Bogbean. Chris Gibson/English Nature

area at about 1-15cm deep, where water plants will flourish. The margins should be very gently sloping in at least some places, so the finished pond merges naturally into the land. Ideally, create a ‘drawdown’ zone, a very shallow (5cm or less) area, which you can cover with gravel and round stones, to form a beach and protect the liner in summer. Flooded in winter, it will partly dry out in summer, making a fabulous habitat for many insect species, and a great bathing area for birds. Constructing your pond • You can make a pond in any month but early autumn is perhaps the most practical season, when the ground is neither too hard, dry nor cold. Garden ponds

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• You don’t want to put a spade through an underground pipe! Check your site plans for evidence of buried cables or pipes. You can usually work out where the drains run by following the inspection covers. • Unless you garden on heavy clay, you will need a liner. For very small ponds you can buy preformed liners of plastic or fibreglass, but some of these don’t have gently-sloping sides for animals to escape. Some gardeners use concrete, but this is a major undertaking, and can be very expensive. Most people use a flexible liner. The best ones are of butyl or EPDM rubber, and should be guaranteed for 25 years. Don’t be tempted by cheap polythene. This often splits and punctures within a couple of years.

Pond watching. Bob Gibbons

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• How big a liner do you need? Measure the greatest length and width of the hole and then the depth. Add twice the depth to both of the other dimensions. This means that if the length is 3m, the width 2m and the depth 40cm then you need a liner 3.8m long and 2.8m wide. Allow for extra liner so that the edges can be buried in the surrounding soil. • When you have dug the hole, remove all sharp projecting stones or roots that could puncture the liner. This is time consuming, but essential. Locating and repairing holes later is extremely difficult! Add a 2.5cm layer of damp sand as further protection, or use a fabric layer. Old carpets cut to shape will do, although they will rot eventually and become ineffective. Alternatively, buy

For large and ambitious projects Most garden ponds don’t need planning permission. But if you are making a very large pond, if it is close to your boundary (especially if this is a road or footpath) or on agricultural land, contact your planning officer and ask for advice. Officers are almost always helpful and often interested in ponds themselves. If you are going to take water from a river or stream or discharge water into one, you will require a licence from the Environment Agency. In any case, if your garden is on the flood plain of a river, you must consult the Environment Agency, especially over the removal of spoil.

Ponds and safety It is essential to plan your pond with safety in mind. The following steps will help to reduce risks for young children: • Keep the pond shallow, and have wide, very gentlysloping margins all round.

• Have plenty of marginal plants, especially where sides are steeper. • Don’t let the pond surface become completely covered with duckweed or other floating species, which can make a pond look like an area of flat ground and encourage children (and dogs) to walk into it. • Fence the pond securely. The fence should be at least 110cm high, and with close vertical posts that can’t easily be climbed or squeezed between. However, make sure that you can get over or through the fence immediately in case a child somehow manages to get past. • Strong plastic or metal meshes to keep children completely away from the water are now commercially available. These are only really appropriate for smaller ponds, and must be properly installed so children can’t get under them. Safe commercial models are advertised in garden magazines.

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thick polyester matting from lining suppliers. If you have put in a beach area, it can be a good plan to put an extra layer of surplus trimmed-off liner over the liner on the beach, to help protect it from people’s feet and dogs’claws. • What to do with the spoil? A pond two metres by three metres and 50 cm deep in the middle will create two cubic metres of loose soil. If the garden is on a slope, use some of this to ensure the sides of the pond are level all round. Many people use the surplus soil to make a rockery or a bank nearby, and these features can be great winter refuges for amphibians. Make sure the rocks come from a sustainable source, and not from rain-sculptured limestone, and plant the bank with native species to provide cover all year round. • Digging is hard but satisfying work. Hand digging makes it easier to make modifications and adjustments as you go along. For big ponds, if you have vehicle access, you could hire a minidigger or approach a contractor for a quote. One digger and its operator can do a huge amount in a day for a modest rate, but make sure that you agree plans and costs in advance. • Hide the edge of the liner. For most of the pool, the best way to 10

do this is to use turf. The grass will grow into the pond, making it easy for animals to climb in and out. Beach areas should be covered with fine pea gravel (not sharp edged pieces) and round or flat stones. As silt collects between the stones, plants will start to colonise, so you will protect the liner and have an attractive area of habitat as well. • You don’t need to spread subsoil over the pond bottom to encourage plants. And NEVER put topsoil into a pond, because you will bring in unwanted nutrients. For more details, consult one of the excellent guides listed at the end of this leaflet. Ponds and the rest of your garden For many animals, the quality of habitat outside the pond is just as important as the water itself. This is especially true for frogs, toads and

Amphibious bistort. Chris Gibson/English Nature

Smooth newt. Chris Gibson/English Nature

newts, which spend most of their lives on land, using the water mainly to breed. A very formal garden will offer no support for these amphibians, which need dense cover and a plentiful supply of insects and worms for food. Set aside a proportion of your garden to help them, with dense, shady, shrubby borders and areas of long grass under trees. Leaving a few areas unkempt is great for wildlife, and you can provide over-wintering habitat by making piles of logs in a quiet shaded area. Rockeries make good amphibian habitat too. Bog gardens are wildlife assets. Create one when you make your pond. A bog garden is an area which is permanently damp, in which moisture-loving plants can thrive. Dig a hole about 30cm deep, line it

with butyl and then just refill it with the extracted soil. A bog garden can look wonderful next to a pond, especially if it’s located so that surplus pond water drains into it naturally. Dense, lush vegetation in bog gardens is superb habitat for newly-emerged young frogs. Bog gardens also support some very attractive native flowers.

Common toad. Roger Key/English Nature

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Native plants for your pond Plants are vital components of your wildlife pond, providing both habitat and food for a host of animal species. Wildlife ponds should have much of their water surface covered by a good variety of plants. The more complicated the underwater ‘architecture’ of roots, stems and leaves, the more animal species can co-exist. Very few animals like clear open water, where they are easily spotted and eaten by fish.

plants live with all or most of their structure underwater. They offer a very valuable habitat for animal species in deeper water, and help mop up surplus nutrients. Floating leaf plants have their leaves on the water surface in summer, and provide shade and cover. Floating sweet-grass provides some of the best habitat, and is excellent for growing over the edge of the liner, giving a natural look.

Although some plants can colonise ponds very quickly, people will want to introduce plants of their own choice. It is important to plant native species, to which our native animal species are adapted. The species in the table (see pages 14-15) are all attractive and easy to establish.

Emergent plants include some attractive species. They prefer shallow water to root, forming excellent invertebrate habitat, but most of their summer growth is out of the water. They include rushes and reeds, as well as some very fine flowering species, but some are just too vigorous for a small pond.

Water plants fall into four rather artificial categories. Submerged

Marginal and bog plants thrive at the water’s edge or in wet soil. They

Left: Fringed water-lily. Right: Water mint. Chris Gibson/English Nature Facing page: Parrot’s feather. This introduced plant can quickly smother even a large pond. Bob Gibbons

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Native plants for garden ponds

Submerged plants Curled pondweed (Potamogeton crispus) Water starwort (Callitriche stagnalis) Rigid hornwort (Ceratophyllum demersum) Water milfoil (Myriophyllum spicatum)

1 1 1 1

Water crowfoot (Ranunculus aquatilis)*

1

Floating leaf plants Broad-leaved pondweed (Potamogeton natans) Frogbit (Hydrocharis morsus-ranae) Floating sweet-grass (Glyceria fluitans)

1 2-3

Yellow water-lily (Nuphar lutea) Fringed water-lily(Nymphoides peltata) Water soldier (Stratiotes aloides)

2 2 2-3

White water-lily (Nymphaea alba)

2

3

Shallow water emergents Amphibious bistort (Persicaria amphibia) Water forget-me-not (Myosotis scorpiodes) Lesser spearwort (Ranunculus flammula)

1 1-2 1

Spearwort (Ranunculus lingua) Arrowhead (Sagittaria sagittifolia)

2-3 1-2

Brooklime (Veronica beccabunga)

1

Bogbean (Menyanthes trifoliate)

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Suitable for

2-3

Comments

Also fennel pondweed (P. pectinatus) Floating rosettes of rounded leaves Thickly-tufted plant, vigorous Caution! NOT Myriophyllum aquaticum Partly floating, attractive white flowers

Excellent for habitat Attractive white flowers Good habitat; plant at the margin to float out ‘Brandy bottle’: smells of alcohol Fringed yellow flowers like buttercup Impressive spiky plant that sinks in winter Beautiful, but too vigorous for most gardens

Pink flower stalks, dark green leaves Small, pale blue flowers Less spectacular, less invasive than spearwort Giant water buttercup, to 90cm high Arrow-head leaves, and small white flowers Blue flowers, straggly, good at the pond edge Beautiful, invasive but easy to control

Native plants for garden ponds

Suitable for

Tall emergents Flowering rush (Butomus umbellatus) Branched bur-reed (Sparganum erectum) Water mint (Mentha aquatica)

1-2 3 2-3

Water plantain (Alisma plantago-aquatica) Greater pond-sedge (Carex riparia) Lesser bulrush (Typha angustifolia) Common reed (Phragmites australis)

2 2-3 2-3 3

Marginal and bog plants Bugle (Ajuga repens) Marsh marigold (Caltha palustris) Hard rush (Juncus inflexus)

1 1-2 2

Lady’s smock (Cardamine pratensis) Yellow flag (Iris pseudacorus)

1 2

Ragged robin (Lychnis flos-cuculi) Purple loosestrife (Lythrum salicaria) Yellow loosestrife (Lysimachia vulgaris) Marsh woundwort (Stachys palustris) Great willowherb (Epilobium hirsutum) Hemp agrimony (Eupatorium cannabinum)

1 2 2 1-2 3 3

Royal fern (Osmunda regalis)

2-3

Suitability

Comments

Very pretty pink-flowering rush Unusual spiky flower, semi evergreen Pretty, scented leaves, invasive, good for bees Small pink flowers, up to 1m high Makes good invertebrate habitat Not for small ponds Fine plant, but too big for most ponds

Very pretty, deep blue, good for insects Superb low yellow-flowering plant Less invasive than soft rush; brown fruits Pretty pale purple flowers Superb yellow flowers, red seed capsules Pretty, delicate pink flower Great red-purple spikes Fine yellow-spiked plant Pale purple flower spikes Tall red-flowered plant, seeds freely Impressive red-purple flowers, seeds freely Superb native fern, dislikes lime

1 2 3

Plants appropriate for all ponds, including small ones. Plants rather too big or vigorous for smaller ponds. Plants best reserved for larger ponds only.

*

Most crowfoots do best where the water level drops to expose a muddy margin on which the seeds germinate.

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Floating pennywort Hydrocotyle ranunculoides - a plant to avoid! Bob Gibbons

include some real beauties. If you’ve made a bog garden alongside your pond, you can really go to town with some stunning effects, while providing cover for frogs, toads and newts. Non-native plants Ideally, a wildlife pond should only contain native species. But there are attractive exotics. These can still provide cover for wildlife although they are less likely to be food plants for insect visitors. Use them sparingly, letting natives form the bulk of the planting. Beware, too, of the problem plants below!

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Invasive aliens The words recall science fiction, but the danger is real enough. Many species of imported plants have escaped from garden ponds into the wild. A few are causing very serious ecological damage to ponds and rivers, through their ability to spread from small fragments and form dense choking mats of vegetation. NEVER plant any of the following aquatic species in your pond (which they would take over in no time). Be careful, because some of these species are still on sale in garden centres. • Fairy or water fern (Azolla filiculoides)

• New Zealand pygmyweed or Australian swamp-stonecrop (Crassula helmsii) • Parrot’s-feather (Myriophyllum aquaticum) • Floating pennywort (Hydrocotyle ranunculoides) • Canadian pondweed/Nuttalls pondweed (Elodea canadensis/Elodea nuttallii) • Curly waterweed (Lagarosiphon major) If you think any of these species may have colonised your pond, don’t

panic, but physically remove all you can, compost the plants, and keep doing so until you are sure they have disappeared. Under no circumstances dispose of even a fragment of any of these plants in the wild! Where to get plants It’s illegal to uproot any wild plant without permission from the landowner, although you can collect seed. Your best source may be

Above: Crassula helmsii - another invasive. Bob Gibbons Top right: Who needs the cultivated variety when the native one is as beautiful as this? Marsh marigold. Chris Gibson/English Nature Bottom right: Frogbit. Chris Gibson/English Nature

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neighbours, friends or a local gardening club, who will usually be able to spare cuttings of their own pond stock, but watch out for aliens! Often, your local wildlife trust will be doing management work on a reserve pond, and may be able to provide material. There are some excellent specialist native plant suppliers, many of them listed on Flora Locale’s website www.floralocale.org. Although many garden centres now sell native species of pond plants, these may be ‘improved’ garden varieties, which are actually of less use to wildlife. The double-flowered variety of marsh marigold – Caltha palustris plena – is one to avoid. Some centres still sell the invasive plants mentioned earlier, and their native stock may be contaminated with exotic species.

Great pond snail. Garth Coupland

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Managing your pond plants Once established, most water plants grow extraordinarily fast unless they are heavily shaded. This means they compete for space in a small pond and need management. Some plants like bogbean send out long runners and can spread two or three metres in a season, but are easily reduced because the brittle stems can be snapped. Others, like the common reed – only suitable for the very largest ponds – form dense, tough, root masses that need a saw to cut them back. Don’t over-manage your pond plants. Remember, they are home for the animals in the pond, so leave them alone during the summer, especially the grasses growing out from the lawn with leaves spreading into the pond margins. It’s best to remove

Water scorpion. Roger Key/English Nature

Migrant hawker. Paul Keene

Animals in your pond

interest for many people. There could be dozens of species in a good large garden pond, although some will be too small to see without a microscope. Getting animals into your pond is easy – they find their own way, provided the water quality is good and the right plants are established. Frogs, toads and newts will discover your new pond quickly, usually within a season and even in most heavily urbanised areas. Insects fly in, and arrive within days. Other animals, like snails and small crustaceans find their way somehow. They travel on the feet of ducks or bathing birds, or arrive attached to introduced plants.

Although plants are beautiful and valuable in their own right, it is the animals that provide the greatest

Animals play many roles in ponds. Freshwater shrimps eat organic debris and rotten vegetation. Water

excess vegetation in the autumn, when most amphibians have left the pond. The submerged plants in particular may have grown very strongly. Pile the material by the pond for 24 hours, so that the tougher trapped animals have some chance to escape, but don’t let it begin to rot there, or nutrients will leach back in to the pond to cause algal problems. Pond plants compost quickly and well. NEVER put any material from your garden into a wild pond. You could unknowingly be releasing a problem species or disease into the wild.

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Emperor dragonfly. Dave Sadler

fleas and others consume bacteria and tiny single-celled organisms living in the bottom sludge or as plankton in the open water. Herbivores, including snails, mayflies, caddis-flies and some beetles, eat larger algae and plants. Other species are predators, eating other animals, and then themselves

Thirsty hedgehog. Mike Powles

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Great diving beetle. Roger Key/English Nature

being eaten by bigger predators. Some live all their life in the pond, while others, like the dragonflies, stay there for several years as flightless larvae, before enjoying a brief period as flying hunting adults and then returning to the pond to lay their eggs. Birds, bats and beasts Once your pond is established, it will be a magnet for other animals. Many garden birds such as blackbirds and starlings will bathe at the edges, and others will come down to drink. You may see house martins and swallows dipping for drinking water as they fly or landing to collect mud for their nests. Garden ponds are often staked out by herons on the look out for prey. If you are very lucky, you may see the whirring blue flight of a kingfisher, although they rarely find the small fish they want in garden

ponds. Grass snakes may visit or even take up residence for the summer if there are plenty of frogs to eat. If you watch a pond at dusk you are likely to see bats, probably pipistrelles, flying over the water, attracted by emerging insects. Hedgehogs and even badgers may stop for a drink, although you will be fortunate to see them. Frequently asked questions about ponds I already have a garden pond - what can I do to make it more wildlife friendly? Formal ponds are not designed for wildlife. They tend to have steep sides without extensive shallow

areas. Concrete fish ponds can be difficult for animals to escape from and few have extensive vegetation cover. To help wildlife, first ensure that frogs and hedgehogs can leave the pond, using rocks, stones or paving slabs as a ramp. Then, create more shallow habitat. Use sandbags, recycled bricks or building blocks to make a retaining wall near the pond edge, and backfill to near the water surface, using stones, gravel or subsoil (NOT topsoil). This will produce shallow water habitat in which plants can get established. Remember that a complicated underwater ‘architecture’ will support more animal species. Finally, do you really want those fish? If you can bear to give them away (don’t release them into the wild!), or just not replace them when

House martins collecting mud for nests. Bob Gibbons

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the heron has breakfasted, you’ll enjoy many more species of animals in your pond. Should I put in a fountain and filter to keep the water clear and oxygenated? These aren’t needed for a wildlife pond. Pond filters take out suspended particles – but also the plankton essential to a healthy pond. They are only needed in over-stocked fish ponds. Fountains help maintain oxygen levels in fishponds, but oxygen isn’t a problem in a balanced wildlife pond. For all that, fountains and waterfalls can make attractive features and they do no harm at all to wildlife. Should I put a net over the pond to keep leaves out in autumn? It is difficult to net larger ponds, and it isn’t necessary unless the pond is right under a large tree. Sometimes frogs, grass snakes or birds can get tangled

The grass snake is the largest British snake. Harmless to humans, it can spend much of its time in water, often feeding on frogs. Andy Sands

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in, or trapped under nets. A moderate input of leaves does no harm. Leaves have little fertilising ability, but are food for many small organisms. It is best to use a rake to remove excessive leaves, and put them into the compost heap. I’m finding dead frogs in and around my pond – what is the problem? Although most frogs hibernate under cover on land, a few over-winter in the bottom of ponds. If the water is frozen for a long period, some frogs may be killed by a build up of toxic decay gases. Bodies may float to the surface in spring. Occasionally, female frogs are drowned during the mating period by over-attentive males. The most serious cause of death is the newly imported Red Leg Disease, a viral complaint that causes starvation, unpleasant ulceration and eventually death. If your frogs look unwell, look up the Froglife website

The linnet is one of many bird species that may drop in for a quick drink. Chris Gomersall

Both photos Bob Gibbons.

at www.froglife.org, where you will find photographs of diseased animals, and a reporting sheet to help track the spread of the disease. There are no frogs or newts in my pond. Where can I go to get some? If the conditions are right in the pond and the garden and if there is another pond within half a kilometre or so from which they could migrate, amphibians will find their own way. The process can take up to a year although it is normally much quicker. Alternatively, bring in a couple of masses of frogspawn, collected from other gardens. Ideally, get spawn from more than one source to avoid inbreeding – but never from the wild. Check with the owner that the “parent” pond doesn’t have a frog disease problem. Newts are best introduced as adults but great crested newts are specially protected and it is illegal to move them at any stage of their lifecycle.

However much frogspawn you have in your pond, only a tiny number of eggs will develop into adult frogs.

I have too much frogspawn in my pond, where should I put it? You will have frogspawn according to the number of frogs surviving in and around your pond, so there won’t be ‘too much’. Nearly all tadpoles die and are eaten each year, the huge numbers in early spring dwindling to only a few young froglets by the summer. Don’t move frogspawn from your pond to the wild as you may inadvertently spread diseases. You will also increase the survival chances of the remaining eggs and so may finish up with more, rather than fewer frogs! My pond develops a thick layer of green weed or duckweed. What is wrong? Blanket weed and duckweed are natural components of pond communities, and both in moderation are excellent habitat. However, duckweed can spoil the appearance of a pond and is almost impossible to Garden ponds

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Foxes occasionally visit garden ponds but you may need to be an early riser to see one. Mike Lane

eradicate. A heavy build-up of blanket weed or duckweed usually means there is too much fertility in the water. The likely reason is nutrients in the water supply. Using tap water is often a cause. Another may be run-off from a fertilised lawn or flowerbed. If you can’t improve the water supply, there are other ways to reduce the problem. Remove all blanket weed with a lawn rake as it builds up, and compost it. Duckweed can be skimmed away. Remove dying vegetation each autumn, and cut back the plants hard so they have plenty of opportunity for new growth next year. Removing vegetation will limit nutrient build up, and fast growing plants next year will compete for nutrients with the algae. Immersing small bags of barley straw is an effective natural control for blanket weed, although it won’t provide more than a temporary fix.

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The larvae of dragonflies are fearsome predators, taking tadpoles and even small fish. Roger Key/English Nature

My old pond dries out in the summer. Does it need digging out? Drying out is common in older ponds with a build-up of silt and organic matter, but these old temporary ponds can be extremely good for wildlife. They usually hold water for long enough in spring for successful amphibian breeding, and acquire a special set of species which tolerate partial drying out. Why not dig a small new pond next to the old one, to restart the succession process? If there isn’t space for this, and you want standing water all year, dig out only part of the old pond, to preserve some of the valuable drying habitat. How can I stop my pond freezing over in winter? Frozen water isn’t really a problem unless you are keeping fish, or if there are a lot of over-wintering

frogs. Even then, you only need a small hole to allow gases to escape. Float a large ball on the surface to keep a vent open. Alternatively, make a hole by resting a saucepan of hot water on the ice to melt through. Never hit the ice with a hammer to break it as the vibrations can kill sensitive animals throughout the pond. Enjoying your pond Don’t just spend time working on your pond – give yourself time to stop and enjoy it, and the fascinating creatures it contains. All sorts of birds visit ponds including pied wagtails and their beautiful (unfairly named!) cousins, grey wagtails. In the early morning you may glimpse a

Arrowhead. Chris Gibson/English Nature

fox coming to drink. In the heat of the day, watch the dragonflies and other insects flying over the pond, mating and laying eggs. Look out for dragonfly larvae emerging and hatching into winged adults - one of the most extraordinary events you can witness in a garden. In the evening, don’t forget to look for bats. Use the books on ponds and pondlife listed on page 26 to discover what species you have in your pond. The easiest way to study small invertebrates is to catch them with a fine kitchen sieve, and study them in a white plastic tray. Why not build up a list of species from season to season and year to year? Eventually, you may become a pond expert yourself!

The grey heron may not always be a welcome visitor. Bob Gibbons

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Finding out more The Ponds Conservation Trust, 1999. The Pond Book: A guide to the Management and Creation of Ponds. Oxford. Order through www.pondstrust.org.uk Louise Bardsley 2003. The Wildlife Pond Handbook. New Holland, London. Peter Robinson, 2003. RHS Water Gardening. Dorling Kindersley.

This is one of a series of English Nature leaflets about gardening with wildlife in mind. The others are: Reptiles in your garden; Amphibians in your garden; Wildlife-friendly gardening: a general guide; Composting and peat-free gardening; Plants for wildlife-friendly gardening; and Meadows in your garden. In preparation: Dragonflies and damselflies in your garden. All leaflets are free and can be obtained from the Enquiry Service on 01773 455101 or e-mail: [email protected]

Trevor Beebee 1995. Pond Life. Whittet Books. Lars-Henrik Olsen, Jacob Sunesen and Bente Vita Pedersen 2001. Small freshwater creatures. Oxford University Press. D.G. Hessayon 1993. The Rock and Water Garden Expert. Transworld Publishers Ltd, London. P.S. Croft 1986. A Key to the Major Groups of British Freshwater Invertebrates. Field Studies Council. The freshwater name trail, and Guide to the reptiles and amphibians of Britain and Ireland. Field Studies Council AIDGAP leaflets.

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Small wildlife pond. Bob Gibbons

English Nature also produces an interactive CD, Gardening with wildlife in mind. This has detailed texts and photos of 500 plants and 300 ‘creatures’ and shows how they are ecologically linked. It costs £9.99 (add £1.50 postage and packing) and can be obtained from The Plant Press, 10 Market Street, Lewes, BN7 2NB. Alternatively call John Stockdale on 01273 476151 or e-mail [email protected]

Useful organisations Pond Conservation: The Water Habitats Trust, BMS, Oxford Brookes University, Gipsy Lane, Oxford OX3 0BP. www.pondstrust.org.uk Froglife, White Lodge, London Road, Peterborough PE7 0LG. www.froglife.org Flora Locale, 36, Kingfisher Court, Hambridge Road, Newbury RG14 5SJ. www.floralocale.org

The Herpetological Conservation Trust, 655A Christchurch Road, Boscombe, Bournemouth, Dorset BH1 4AP. www.herpconstrust.org.uk The Wildlife Trusts, The Kiln, Waterside, Mather Road, Newark NG24 1WT. www.wildlifetrusts.org Plantlife, 14, Rollestone Street, Salisbury SP1 1DX. www.plantlife.org.uk

Above: Azure damselfly. Robin Chittenden Above right: Brooklime. Chris Gibson/English Nature

Royal Horticultural Society, 80, Vincent Square, London SW1P 2PE. www.rhs.org.uk 27

English Nature is the Government agency that champions the conservation of wildlife and geology throughout England.

Pond Conservation is the national charity working to conserve and protect ponds and small water bodies through research, training and practical management and creation projects.

This is one of a range of publications published by: External Relations Team English Nature Northminster House Peterborough PE1 1UA www.english-nature.org.uk © English Nature 2005 Printed on Evolution Satin, 75% recycled post-consumer waste paper, elemental chlorine free. ISBN 1 85716 856 9 Catalogue code IN16.9 Designed and printed by Astron Corporate Solutions. 15M.

Front cover photographs: Top left: Pond skaters may arrive at new ponds within days. Roger Key/English Nature Bottom left: Broad-bodied chaser. Paul Keene Main: The kingfisher is an unlikely visitor to most ponds but can turn up almost anywhere near water. Chris Gomersall