The Very Small Pond


The Large Puddle


John Rogers



If you give the pond time to settle after filling, time to mature after planting, and introduce just a few fish and some pond snails, the pond will reach a state of balance. If you start adding chemicals, you'll always have to add chemicals.

Goldfish are hardy, fun, and cheap. You don't need to feed them, cosset them and protect them from thieves (except possibly the neighbour's cat).

Ill-chosen plants can choke your pond, but you can still be spectacular - use tall thin plants, not low flat ones. If you like water lilies, get the smallest you can. For the rest of the shade you'll need, buy a floating plant like water lettuce every year (just one, they'll multiply).

If you make it a daily task to skim the surface for pond weed and dead leaves it'll take about five minutes. If you leave it for six months you'll have a filthy job cleaning the pond and you'll probably put your back out in the process. Don't ask how I found out!

Running water is great, not just for the appearance or even for the soothing sound, but because it keeps the water aerated. It doesn't have to be fancy, but it'll keep the pond much fresher.


Your comments on these pages are welcomed, bearing in mind that, like the pond, they are always under development.

Send them to

The frog


This page is about small ponds.

 In my ignorant youth, I was foolish enough to buy a book entitled "The Small Garden", in the hope that it would be useful in planning my 20 square yards of garden and 15 square yards of concrete. The smallest garden in the book was 44 square yards and the largest was a quarter of an acre. For me, the book was in the nature of a chocolate teapot - decorative but utterly useless.

 So, this is about small ponds. You may be assured that I won't show you how to emulate Versailles or restock Loch Ness. I hope only to show that anyone with the smallest garden can enjoy the peace and fascination that only a water garden can provide.

 After making every mistake in the book, I have built ponds that have survived and flourished and my advice will be based on personal experience. I don't claim that mine are the only answers or that I will tell you all the intricacies of pond design. There are many detailed and lavishly illustrated books that describe every kind of pond, liner, pump, plant and fish that you could wish to have in your quarter-acre small garden. What I will do is to outline the vital questions you will have to face and to give answers that have worked for me and will work for you.

  I would like to take this opportunity of acknowledging my debt to a remarkable book, "Pond Life" by John Clegg, Bloomsbury Books (ISBN 1-8547-1063-X). This little pocket book, published in 1956 and regularly reprinted since, was the first that taught me how a piece of the natural world fitted together. Today we call this 'ecology'.

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 Have I got room for a pond?

 What kind of pond should I build?

 Where should I build my pond?

 Should my pond have running water?

 Preshaped or flexible liner?

 What plants should I have in the pond?

 What animals should I have in the pond?

 Can I build an indoor pond?

 What questions do people ask?

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Have I got room for a pond?


 Well, almost certainly yes. You can get a fountain that will fit in a smallish indoor plant pot or window box. I got mine from Waterstone Fountains of Cheddar (Tel/Fax +44 1934-744408), and am delighted with it. You won't be able to keep four-foot Koi carp, but you'd have to sell the house to pay for them anyway.

 My smallest outdoor water feature is a simple plastic plant pot 30 inches by 12 inches by 10 inches deep, planted with a pygmy water lily and a couple of shallow marginals. You can even get a two-foot square rock pool with mini-stream and fountain (it's made of stone-effect plastic, but it looks remarkably convincing built into the garden).

 For frogs, toads and other wildlife 2 feet by 18 inches by 9 inches will suffice. For goldfish, a pond 4 feet by 3 feet by 12 inches will do very nicely. If you're still thinking about Koi, you're reading the wrong page. They're finicky, expensive and need a pool that looks like an oil storage tank. Goldfish are visible, cheap, easy to feed and tough. Your family/neighbours/environmental health officer will complain about the pond long before the goldfish do.


What kind of pond should I build?

It all depends what you want from your pond. Despite what you may read, it is possible to combine wildlife, fish (no, not Koi, please browse another page), the sound of moving water and the beauty of water lilies.

 If you're planning on a water garden for plants alone then a damp and dismal patch a là Eeyore will do nicely. If you want to grow water-lilies then the pygmy varieties will need 2 square foot surface area and 9 inches depth. In a small pond, anything bar these pygmy varieties will give you problems with over-crowding. By which I mean, don't grow them.

 If you are going to encourage frogs and toads then they must have access between the pond and the garden. This doesn't rule out raised ponds - amphibians are remarkably stupid except in their ability to find and use a ramp back into their pond. They'll also need somewhere to hide from cats, dogs, foxes and sunlight. Either rough undergrowth or rude stone shelters will suit. If you put the pond in the middle of the lawn, some of the beasties will survive the trek to shelter, but many won't.

 If you want to keep fish, then you'll need a minimum depth of 12 inches and 9 square feet of pond surface. I'd be nervous about less than 4 feet by 3 feet myself, but then I'm a pessimist.

There is a lot of discussion in pond design books about formal versus informal ponds. My feeling is that for a small pond in a small garden, raised ponds (or the raised side of ponds cut back into a slope) should be formal, and sunken ponds informal. This is purely a means of saving space. The formal edge of a raised pond can be vertical, an informal edge must slope into the garden at a shallow angle. Similarly, with a sunken informal pond, plants can be grown right up the water's edge without wasting space on stone slabs. This also makes it easier for the amphibians to leap out to feast on your slugs.


Where should I build my pond?

The stock answer is "in a sunny spot on level ground, but not under trees". Good advice, if you own half of Surrey - unfortunately you have a north-facing garden on a vicious slope and overlooked by your neighbour's lilac tree. (Lilac is a special pain because it drops gunge into your garden twice a year).

 To take these points in order:

 A north-facing garden will, in the nature of things, have a southern end with a south-facing wall under which you can build your pond. The only pond plant that must have lengthy periods of sunshine is the water-lily. If it doesn't get its regulation amount of sun per day it simply won't flower. Mine is in flower for six weeks a year - short of demolishing my house or tilting the earth on its axis that's all I'm going to get. The rest of the pond plants flower beautifully and the wildlife is healthy, so I've learnt to enjoy those six weeks.

 You can, however, be more radical in these matters. My first pond was a raised construction 18 inches from the north wall of my house between a dividing wall and the kitchen extension. It never has seen and never will see the sun. What it has is a quartz-halogen patio lamp on a time switch giving it two hours of high-intensity light a day. Surrounded by ferns and stocked with goldfish, it presents a delightful floodlit scene when viewed from the dining-room and kitchen windows - even when it's raining.

 Level ground is ideal for a pond, if you're lucky enough to have some. A pond may, however, be even more effective cut back into a slope with a raised edge on the lower side. This enables the pond to blend into the garden while still showing a formal face to the world.

 If you have to, you can site your pond near to a deciduous tree, but it will involve a lot of work in autumn. This is less of a problem with a small pond, as it is reasonably easy to cover it with netting to stop the pond being clogged with dead leaves. If this is allowed to happen, it will cause serious problems of oxygen deficiency and black gunge at the bottom of the pond. If you have a choice, siting your pond under an evergreen will make life easier in this regard. Obviously, you should avoid putting the pond in the full shade of the tree.


Should my pond have running water?

If possible, yes.

 Running water is not only, or even mainly, for visual effect. It helps to oxygenate the water to the general benefit of its residents. Its sound makes the hottest day seem cooler and more restful. I am writing this on a scorching day in August beside a pond whose gentle murmur lets me ignore the sweat dripping on my laptop computer. My recently installed indoor fountain (see Have I got room for a pond?) does the same job when I am working on my desktop machine.

 I must emphasise 'gentle'. Despite what you may read, you don't need Niagara Falls combined with the Trafalgar Square fountains (unless you own the other half of Surrey as well). A neat rule of thumb is that your water flow per hour should be not be more than your pond's volume. With our minimum 4 feet by 3 feet by 12 inches fish-pond (8 cubic feet=48 gallons) this would give 48 gallons an hour. Half this amount will give the desired effect without disturbing your water-lilies. If you can't imagine 24 gallons an hour, and most of us can't, turn on one of your kitchen taps to a quarter of its full flow.

 To achieve this gentle flow, you can use a low-voltage pump. These have a mains transformer in the house and provide a 24-volt cable to connect to the pump. This means that you need no mains cabling in the garden. Mains cable is thick and difficult to conceal. The manufacturers say it's safe, and I'm sure they're right, but the combination of mains cable and open water still makes me nervous.

 A neat idea is to fit a hose connector on the output end of the tubing from your pump. You can then clean out the tubing and pump by switching off the power, plugging a garden hose into the connector on your tubing and turning the tap full on.

 The water feature can be quite ridiculously simple and still be very effective. Water pumped out of a pond and flowing back out of the undergrowth under and over a few flat pebbles can achieve all that I have claimed. For some reason, many of the experts seem to ignore the melodic possibilities of running water. Just changing the shape of the edges over which it flows, and the depth of water into which it drops, can alter the note and the resonance of the stream. If you don't believe me, try it with a couple of plates under the kitchen tap.


Preshaped or flexible liner?


 If the size and shape that you want for your pond are available as a prefabricated plastic liner, and you can afford the extra cost, then this is the simplest method. The pond will have ledges at the right depth for marginal plants, the right overall depth for its area and will have the right slope to its sides. It will also force you to take the effort to dig the pond to the appropriate depth. A handy tip, if you are designing your own pond shape, is to imitate the features of the prefabricated liners you will see in your local garden centre. They make them by the thousand, so we have to assume they've got it right.

 If you have an unconventional shape or you want to create a stream then you will have to use flexible liner. DON'T BUY CHEAP LINING MATERIAL. A polythene or light-grade PVC liner will have to be replaced when the sun or a careless trowel eventually destroys it. If you can't afford decent lining material or, as I did, find the quality stuff in a skip, don't build the pond. If I convince you of nothing else, I hope I can save you from the filth, depression and general agony of ripping up a mature pond and its inhabitants to replace a cheap liner. Use butyl or heavy-grade PVC with a guaranteed lifetime.

The construction of the pond is similar in both cases, although the excavation has to be more carefully shaped for a prefabricated liner than for a flexible one, as the latter will always move to accommodate the shape of the hole.


What plants should I have in the pond?

The golden rule here is to remember that this is a small pond.

If you want spectacle, grow upwards! I have a huge Thalia dealbata in my small pond (powdery alligatorflag would you believe?). Huge in the sense that it grows to seven or eight feet high - the surface area it uses is less than a square foot.

 Many of the plants recommended in the how-to books and sold in garden centres will grow to fill your pond before you can blink. Look for pygmaea, minima, nana (dwarf) and other indications of restricted growth. Avoid full size irises, water mint and water forget-me-not like the plague. I have a particular liking for mimulus luteus (Yellow Monkey Musk) but I wouldn't recommend it to anyone who doesn't want to spend half their life chopping it back.

 So what do I suggest? The types of plant we need are:


These are essential for preserving the oxygen balance in the pond.

Surface cover

These reduce the amount of light entering the pond and subsequent algal growth, and also provide shelter for your fish.


These will live in containers on your ledges and will provide much of the colour in the pond. They will also blend the pond with the garden and shelter for your amphibians.


I would always recommend Canadian pondweed elodea canadensis (or anacharis canadensis as the biologists have named it this week). It is cheap, hardy and stays in the pond. It does tend to become rampant, but does not object to being thinned out.

Surface cover

 For a small pond, the problem is finding plants that will cover the 50% of the surface that the experts suggest, but won't cover the entire surface while you turn your head for five minutes.

The pygmy water-lily nymphaea pygmaea is ideal in this respect, being happy in 9 inches of water and producing much smaller leaves than other varieties.

 Water hawthorn aponogeton distachys is also civilised in its habits and often continues to produce its delicate white flowers as late as December.

 Both of these should be planted in containers for ease of maintenance.

In terms of floating plants we have frogbit hydrocharis morsus ranae which resembles an annual miniature water-lily. This will grow to fill the space available but as it has no roots, it is easy to control. It will regrow itself from seed each spring. We also have water hyacinth eichornia crassipes and water lettuce pistia stratoides, that look much as their names suggest. These are both tender, and the books usually suggest that they be wintered indoors. Since they are both reasonably priced and quick to propagate, I bin then in the autumn and buy anew in the spring. Fairy moss azolla caroliniana is a real oddity. It's a tiny floating fern, and on a very small pond is attractive and controllable. Don't let it near anything bigger than 6 feet by 3 feet or you'll never see clear water again - yet another case where small is beautiful.


These will provide the decoration for your pond, and can also cause the most problems by excess vigour. I make no apology for repeating my warning against water mint and water forget-me-not. If I was to state my true feelings about these monsters or to repeat the curses I've uttered while trying to get rid of them, this page would on the alt.curse.blasphemy newsgroup, out of reach of impressionable children. Fortunately most plants do have miniature and less invasive forms.

 One way of making the most of limited horizontal space is to go vertical. Zebra rush scirpus zebrinus is an attractive striped rush that grows to 2 feet without taking up too much space. Similarly dwarf Japanese reedmace (like a bulrush) typha minima limits itself to 1 feet without needing too much elbow-room. Again, plant these in a container.

 I would also suggest lobelia cardinalis. This grows up to 2 feet tall and produces the most stunning deep red flowers in late summer. It's not strictly an aquatic plant, but the only way to keep it from slugs and snails is to grow it in a container under water. Otherwise the beasts will wait undercover until the flowers just begin to open and scoff the lot.

 In terms of decorative and flowering plants for the pond edge, I have already warned you about mimulus luteus. I like it so I put up with the hacking back. Polygonum affine is a small and well-behaved plant that shows red flowers throughout late summer. Japanese knotweed, hottuynia cordata is a terror, particularly for lawns, but the variegated variety 'Chameleon' is much less invasive and stunningly coloured. If you are worried about this, growing it on an island or in a container should avoid the usual problems. The various varieties of speedwell or veronica all do well at pond edges and provide you with ground cover and delicate blue flowers. Bluetts houstonia caerulea do a similar job.

 Other than these particular pond-side plants almost anything will grow happily on the banks. For those areas without much sun, I'd suggest ferns and hellebores, but I'm sure you know as much about this as I do. Just to repeat, it's not a good idea to plant deciduous bushes near the pond. Also spiky evergreens will help to provide shelter for the residents to escape into the shrubbery. I'll take this chance to plug my absolute favourite, Juniper 'Blue Star' juniperus squamata.


What animals should I have in the pond?

As far as amphibians are concerned, frogs and toads will generally find your pond for themselves. If you are totally surrounded by concrete, then a trip to a local pond in spring will usually find plenty of spawn. You could also try your local garden centre. I find they're usually grateful to have someone to take frog-spawn off their hands. Don't take newt-spawn from the wild; firstly it's illegal, and secondly the adults will eat everything in your pond.

 You may have been brought up to think of these beasts as slimy and unpleasant. They're not. They're fascinating to watch and toads in particular will give your slugs the fright of their greedy little lives. Of course, if you love slugs...

 When thinking about fish, stick to goldfish, and the plain varieties at that. The ones with bizarre deformities so beloved of the Japanese and other fish-fanciers are unsuitable for anything but the equivalent of the intensive-care ward, the indoor aquarium. You can get away with colour variations, if you like the exotic, and there's a rather fetching Chinese orange and black variety that seems robust enough. The occasional unpigmented 'ghost' goldfish is sometimes seen, and these also live quite happily in the real world. Basically fish-shaped fish survive and the others don't.

 Loach will also survive perfectly happily but, after you put them in the pond, you will never see them again. This is because they are a) brownish and b) bottom-feeders. If you like the idea of invisible fish, buy loach; otherwise stick with goldfish.

 Get your fish from a reputable aquatics shop. If you find a reliable supplier, stay with him. Some general pet shops supply fish that not only have a desperately short life expectancy, but may also infect your healthy stock. Don't even think about fairground win-a-goldfish stalls, although I imagine that all these have been torched by animal activists.

 Allow 2 square feet of pond surface per inch of fish. (That's a starting figure - if you're doing it anything like right, those fish are going to grow). As an example, our minimum 4 feet by 3 feet by 12 inches fish pond will take 6 one-inch baby goldfish that will grow to two inches in a year or so.

 Oh, and by the way, don't even think about Koi. I think I may have mentioned this before.


Can I build an indoor pond?

This item was inspired by a query from Janet, a fourth-grade teacher in the States.

 Yes, indoor water features are freely available, from desk-sized mini-fountains to massive aquaria full of piranhas, alligators, and in Texas very probably Great White Sharks. What I will try to describe here is something slightly different, a slice of natural wetland in an indoor tank.

 In order to show the interdependence of the natural world (the ecology), you will need a number of micro-environments. These are:

In order to make all these levels visible we will need a glass-fronted container. For safety's sake the tank front, at least, must be made of toughened glass; plastic would provide the safety factor, but is terribly prone to scratches. I would expect such tanks to be commercially available.

The tank should be set up with the water surface slightly above eye-level. To allow for different heights of observer and areas of interest, there should be graduated steps in front of the tank.

In order to allow photosynthesis to take place, the tank should either receive natural sunlight from above or should have some form of 'daylight' lamp to provide the necessary light.

 Air must be allowed to circulate freely between the tank and the world outside, but some form of netting is vital to prevent insects from taking over the building in which the tank is housed. Mosquito larvae are educational, a plague of mosquitoes tends to be unpopular.

 The plants in your pond will be similar to those described in What plants should I have in the pond? If you are looking for local authenticity, you can include plants gathered locally. In both cases look for low-growing plants. The restrictions on space are the exact opposite of those for the outdoor pond, where we use the unlimited vertical space to get over our limited horizontal space.

 In stocking the pond, you must remember that a garden pond gets a lot of its residents by accident. Passing frogs will spawn in the pond, damsel flies and pond skaters will lay their eggs and, in no time at all, you will have more wildlife than you could shake a stick at. The only animals you will have to add to a garden pond are the fish.

 The opposite is the case with an indoor pond.

 When deciding what to add, a lot depends on the local wildlife. As regards fish, I would expect just the smaller species, loach and minnows in this part of the world, or goldfish if you're not too worried about authenticity. Otherwise, a netting expedition in a local pond/waterway may provide you with what you need.

 You can get the insect life by scooping up some bottom mud from a local wild pond around late October/early November. Most of these beasties lay eggs in late summer. Adding some pond snails (available from your local pond supplier) will provide extra interest and help to keep the tank glass clear.

 Amphibians are best added in spring by taking spawn from local pond, natural and artificial. This is OK in England, but if you live in the US or Australia, I would recommend asking a local expert, or reading a good wildlife guide, so that you don't find yourself with a pond full of bullfrogs or cane toads.


What questions do people ask?

This is a sample of the frequently asked questions from my mailbag.

 How do I over-winter my pond?

 How do I deal with algae (green gungy stuff)?

How do I build a waterfall?

How do I deal with goldfish eating my plants?

How do I over-winter my pond?

 The first thing to ensure is that the pond is free of dead vegetation, both from pond plants and from wind-blown leaves. If these are left, then they will fall to the bottom of the pond, rot, and reduce the oxygen available to the fish.

If you live in a temperate region and some of your pond is deeper than 20 inches, then the fish should be safe from freezing, due to the anomalous expansion of water. Don't worry about the long words, just be glad of it - without it there would almost certainly be no life on the planet.

 Your pond is only likely to be damaged by freezing if the sides are vertical which, of course, they should not be. If they are, you'll be removing the corpses of small mammals throughout the summer and wishing you'd never thought of a pond. With sloping sides, the ice will push upwards rather that outwards, without damaging your pond liner.

 It's important to ensure that the fish have oxygen throughout the winter, so you should make a hole in the ice when the pond freezes. DON'T break the ice with a hammer or an axe; if you want to know how it feels to the fish try standing inside a church bell while someone hits it with a sledgehammer! Take a kettleful of boiling water and pour it on the ice at the edge of the pond to make a hole in the ice. The fish will be OK, they'll be dozing in the deepest part of the pond.

 What questions do people ask?


How do I deal with algae (green gungy stuff)?

 This consists of long green strands that can quickly clog up the pond. The best way to remove it is to twirl it round a stick and drag it out of the pond. Lay the stuff by the pond so that any beasties caught in it have a chance to get back in. This problem is generally caused by

 a) too many nutrients, for example, nitrates from tap water and garden runoff and fish excreta

 b) too much sunlight

 There's not much you can do with the first of these, although you should be careful what chemicals you use near the pond. The sunlight reaching the pond can and should be reduced by using surface plants like water-lilies and water hyacinth. Oxygenating plants like elodea will also compete with the algae for resources and restrict its growth.

 A good way of keeping algae in check is to put a few pond snails (also known as ramshorn snails) in the pond. These will eat the algae that is fertilised by the fish excreta and the fish will eat the snail eggs - that's what we call ecology! The ideal pond is created not by fiddling with chemicals, but by letting nature balance itself out.

 What questions do people ask?


How do I build a waterfall?

This is probably one of the most interesting (for which read 'difficult') questions that can be asked about pond building.

There are two main approaches:

a) Get pre-shaped rock pools and waterfall sections from your garden centre and build round them.

This isn't as bad as it sounds. Some of these are done in stone effect by coating with adhesive and stone dust, and look quite decent when bedded in and planted up. Although I must admit they look pretty awful in the shop. They must be well bedded in, much as you would do with a pond liner, with a layer of sand or old carpet to protect them from stones.

It is vital to test the system for leaks and splash-overs before putting the earth back around them and planting out. Finding a source of water loss after this is well-nigh impossible. Run the piping from the pump into the top pond and let the system run for 6 hours or so to check this.

b) Build your own watercourse using good quality pond liner and rocks.

This would, as you've probably guessed, be my preference. Dig out the upper pool or pools as you want them, allowing space for sand or old carpet to use as a liner. If you want a cascade, profile the lower edge of the pool to be flat, so that you can cascade the water over a flat stone. (See crude diagrams below).

Get the best liner you can afford or, in my case, rescue from a builders' skip. When you lay it down, be extremely generous and enclose the entire runoff area so that any water escaping from the upper pond will eventually reach the lower one.

Test the system as for a ready-built waterfall, running the piping from the lower pond pump underneath the liner, over the top and into your top pond. Don't be tempted to put on any stones or earth until you're totally sure that the system is watertight. This will actually be easier to see, as you can trace the path of every drop over the liner. The only exception to this is that you can experiment with the flat stones to use as waterfall edges. I use bits of slate, but you can try any local material.

Now add your rocks, trying to obey the usual rules for rock gardens (strata all lined up, similar sized rocks, etc.) and earth, and plant up the area. Click here for more about plants. You can arrange the piping to flow into the top pond from under a stone in the manner of a spring. (A little fiddling here will produce the right sound of water bubbling into the pond)

You'll find that some of the water flows under the waterfall edge stones (although still into the lower pond). I got over this by running a little sand and fine gravel up against the inner side of the stone, where it builds up to form a seal.

Obviously, the same techniques apply if you're going to put another pool between the top and bottom ponds.

 What questions do people ask?


How do I deal with goldfish eating my plants?

If you look very closely, you'll almost certainly see that the goldfish aren't eating the plants; they're eating the beasties that are eating the plants! Generally, the larvae of the imaginatively named water-lily beetle are to blame for eating your water-lilies. When they're all gone the little devils will start on your other plants.

You obviously can't put insecticide in the pond, but if you've got your plants in crates you can:

Put the affected plants in a large bucket of water and treat them with insecticide until the beasts are dead.

Wash out the bucket and fill with new water and stand the plants in it for two weeks or so looking for signs of re-infestation.

Put the plants back in the pond.

 What questions do people ask?