Wildlife Gardening Part 3

Please find Part Three of Wildlife Gardening Made Easy. The larger wildlife pond. Information has been supplied by Noel Brock CEO and founder of Frognal Gardens Ltd,  London.

Wildlife gardening made easy- part three.

The bigger wildlife pond.

What is the purpose of a wildlife pond?

1. To create a permanent and improving home for aquatic and amphibious animals and plants

2. To engage and enthuse successive generations of people, especially children.

These goals are the same whether the pond is in a private garden, or a public space, a nature reserve, or the corner of a farmer’s field.

Building a pond with a flexible liner (butyl, firestone or similar) is a familiar technique, with step-by step instructions available everywhere, so we will bypass that.

What you see nowhere is how to protect that soft liner from deliberate vandalism or even well- intentioned cleaning attempts or, even accidents.

If a wildlife pond is to succeed, to make a real difference to helping biodiversity going forward, it must be permanent.

Too often we see butyl – liner ponds punctured by vandals in local nature reserves, or by careless gardeners in private gardens. The water drains away, and the pond is no more.

Here I will show you how to protect that liner and make your new pond last 1000 years.

Build Your Pond.

First follow the standard instructions for a lined pond.

  1. Dig
  2. Underlay
  3. Liner 

As stated, instructions for this are all over the internet.



Cover the liner with another layer of underlay.

Cover that new layer of underlay with salvaged, broken, old, paving slabs. Any paving slabs …… salvage yourself from council pavement repairs, from your own projects, or you can easily buy them cheaply from any rubbish tip or recycling centre.

Use bricks or concrete blocks to create a troughed shelf around 2 or 3 Arrange the slabs to roughly cover the bottom and sides. Don‘t worry about small gaps.

Make a strong screed mix of about 1 cement: 4 coarse sharp sand, with plenty of plasticiser.

Spread your screed mix over all the slabs, the brick shelves, etc. Push it into the gaps between slabs and spread it thinly over the surface of those slabs. If some slabs do not sit flat, push some screed under Use the screed to secure and cover the little brick “wall” of the troughed shelf.

After 2 weeks, the screed will have gone off nicely, even in winter. Now fill the pond with tap water and leave it 10 days.

After the water has been standing for 10 days (see the blue plasticiser, etc. coming out into the water!) pump it out into a drain. Refill, and repeat the 10-day process 2 more times.

Now it is nice and clean, and all the harmful chemicals from the fresh cement have been washed away.

Please note:

95% of the weight and volume of the protection layer is old,chemically safe concrete or stone. The fresh cement is only joining the pieces, and, more importantly, filling the gaps. That is why the rinsing out of concrete chemicals is quick and total.

When it is finished, tiny cracks will appear between the slabs, all over, because the cement surface is thin. No problem! The liner is there underneath, and safe from damage, because the cement between the slabs is thick. But, the total volume of fresh concrete is very small.

The hairline cracks will not enlarge, even after many years, and the pond is safe. Because 95% of the concrete volume is old reclaimed slabs, the “carbon footprint” of new cement is tiny, as is the use of quarried sand and aggregates, and the old slabs have been saved from landfill!!

Now get hold of some subsoil- just dig down to the clay or other subsoil layer, you will have done that while digging the pond, and reserved it probably. Put this subsoil into the troughed shelf.

About 75mm (3”) depth is perfect. If you want, you can put a similar layer onto the bottom of the deep part of the pond, or put a bit of washed gravel there.

Wildlife Pond Construction

Old slabs and bricks on new underlay.
Ready for Screed.
Screed layer applied.
The pond being rinsed.

Its Time To Plant.

Plant your emergent plants into the subsoil on the shelf. Harvest some reeds, (phragmites), bulrushes (typha) with forgetmenots (mysotis), watercress (nasturtium officinale), carex etc. etc. from a local pond, ditch, stream, or buy from an aquatic supplier.


Get a few good handfuls of submerged water plants like hornwort or canadian pond weed…… get those from a local pond if possible, and put them straight into a bucket of water from the same pond. This is important, because if that local pond is healthy, the bunches of weed will hold dozens of species of invertebrates and the bucket of water will contain dozens more. This will “seed” the animal and plant communities into your new pond.

Now your pond is ready for its 1000-year wildlife odyssey!



New Pond after a few months
A different angle.
The same pond just 7 months in
By 8 months several species of Dragon Fly had arrived. This one is Southern hawker.