How to : Build a cheap garden pond for under £20

It is amazing how quickly, easily and cheaply anyone can build a small garden pond in your own garden. So, here are a few starting points!

Common frog tadpole. Image by Laurie Campbell.

Common frog tadpole. Image by Laurie Campbell.

However before we move into details, why are such ponds so important and why are ponds are often sited as the best single thing that you can do for wildlife in your garden? Watery environments are one of the richest habitats for wildlife and your own pond will quickly attract a whole host of new and interesting wildlife to your garden. You could expect to enjoy frogs, newts, dragon flies and other invertebrate pond dwellers, plus bathing for both birds and mammals in even a diminutive pond.

Your pond would ideally be located away from falling autumnal leaves and in an open area, but full sunlight can make the water too hot in high summer, so select your location carefully. High water temperatures and organic debris both decrease the oxygen content of water, making an anaerobic environment and potentially killing your aquatic wildlife.

Ponds come in all shapes, sizes and complexities. If you have the space and inclination then a large pond is likely to provide a greater benefit for wildlife and allow for more diversity. However, many of us do not have that amount of spare room in our gardens and this ‘How to…’ will only be covering a minimal option that can easily be adopted by many people.

OK, OK, enough of the introduction, let’s get on with it!

Our new pond is going to be constructed from a baby bath! Our little boy is coming up to 2 years old, this meant that his baby bath had become spare, and we took the opportunity to put it to good use. Our son, Jack, was more than willing to ‘help’ with his spade for a short time, before thinking that my spade may be better…………. despite that it was still a quick and easy job.

Putting the pond into our garden took less than an hour, so if you have a little room in your garden, a spare baby bath and a little time then there really is no excuse! If you don’t have a spare baby bath (or some similar structure) then these can be bought brand spanking new for £10, or even less from charity shops, friends or family.

So armed with your potential pond liner:

Common newt. Image by Laurie Campbell.

Common newt. Image by Laurie Campbell.

Choose a spot in your garden, preferably gentle sunshine, to site your pond.

Put the baby bath on the floor upside down and go around the edge with your spade to make out the area.

Move the baby bath out of your way and dig out to the required level, keeping in mind that the bottom needs to be level.

Check that the baby bath fits in the hole as required and that it looks fairly level. At this point, the hardest bit is over and you may wish to take time for a drink, and maybe even a biscuit!

You now need to fill your pond with water. Ideally this would be rain water but tap water is also fine.

Having filled it with water you can either admire your work and compliment yourself on your ‘rack-a’th’eye’ judgment (Yorkshire for good eye judgement), or, like me, you may need to level it further by adjusting the soil beneath it.

Adjust the soil surrounding the edges, top up if necessary and the initial stage is complete.
The pond now needs to be left to settle for at least one to two weeks, although you may wish to add a little garden soil, or even specific pond soil if available (try your local garden centre). This period of time is especially important if you used tap water as it allow the water to lose the chlorine found in it.

After the settling in period you can begin to add aquatic plants. Pond biodiversity is a very complex subject and will be covered in more detail in a later ‘How to…’ article. For starters though, you should always try to ensure that you use native species as opposed to non-natives sold at many garden centres. We added Marsh marigolds (Caltha palustris), Purple Loosestrife (Lythrum salicaria) and Ragged Robin (Lychnis flos-cuculi). These are marginal plants and were all lifted slightly on a thin slab so that they sit about 1” under the water. We will add a native variety of milfoil (Myriophyllum spicatum) and/or pondweed (Zannichelia palustris) when they become available (usually around May), both of these plants help keep the water well oxygenated.

Common Frog. Image by Laurie Campbell.

Common Frog. Image by Laurie Campbell.

It is also beneficial to wildlife if you add plant around the edge of the pond to offer shelter and places to hide. Trailing plants also offer another means of escape.

After a further settling period of at least a month you may wish to speed up the establishment of your pond by adding a bucket of water from an existing pond if you have access to one. If not, don’t worry, wildlife and small organisms will soon find your pond and it will quickly begin to develop.

Depending on the time of year, you may also wish to add frogspawn to your pond to keep frogs coming back year after year. Initially, very small quantity will be best in a pond of this size, and after the first year nature will take over for you.

Before we conclude the article, a few further points need addressing. Firstly and most importantly we need to ensure that anything going into the pond can also get out. Any kind of ramp can be used or a series of stones can be added to ensure that frogs and other creatures can climb back out of the pond. Don’t forget that the ramp must be a rot proof one! This has the added benefit of providing some shade and shelter within the pond.

If at all possible, leave a suitable container in your garden to collect rain water. This can be used to top up your pond during dry periods. Whilst tap water can be used it is not ideal due to the chemicals it contains. If you do need to use tap water, your pond may turn slightly green, but don’t worry, this should rectify itself within a couple of days; if it doesn’t then you may need to manually remove excess growth caused by nutrients found in tap water.

If you have children then you will need to consider some method of ensuring that they cannot fall into the pond, luckily for us, we had to fence off the bottom section of our garden due to steep steps down to it. This means that Jack can only get down there when we take him to look.

Finally it should also be noted that a wildlife pond should not have fish, pumps or any sort of filtration system as these are very damaging to the tiny creatures in the water that other wildlife depend on.

N.B. The article title of under £20 was based on a cost for a baby bath of around £10 and also accounted for the £8 we spent on aquatic plants.