Getting a good natural edge to a wildlife pond is still one of the most difficult parts of the pond construction process – mainly because we don’t yet have much experience of how to do it.
Stone or slab edging is very much easier.
So it was no surprise to get this cry for help from Janet. I had much the same problems making the ‘New Pond’ last year.
So here’s her mail:
‘Hello,
I am currently constructing a wildlife pond and have been following your advice (on internet and in the RHS magazine etc).
However, I was planning to have flat stones round the edge of the pond, not grass. (This will hold down the liner with some hard core and sand.)
I cannot understand how putting the turves back on top of liner will allow the grass to grow. Am I missing something?
And I also thought that by putting turves at the edge, there was a danger of soil slipping into the pond which causes problems.
The pond is one and a half metres across, is circular, is in the lawn, in a sunny spot, and is not too deep. (About 12 inches plus I think.)
Thank you for all your help on the website and in articles.
Janet’
Putting tuves back on top of a liner sounds like it won’t work and the grass will die.
Actually as long as you leave a little soil and roots the grass will grow on top of the liner – it will probably go yellow for a while, unless the weather is very wet, but it will recover and grow on top of the plastic.
After I cut the turves to edge the New Pond I knocked off most of the soil just leaving the mass of grass roots and a bit of soil – doing this is probably enough to keep too much soil from falling in the pond. The turves end up about 1 ½ to 2 inches thick.
Pond edge design - click to enlarge
Here are before and after photos of the New Pond edge turves. It works pretty well.
Here are the turves cut and ready to lay on the liner once it is in place. You can just about make out the low bank of soil in places that stops the water running back into the pond.
Next you can see the turves laid on top of the liner – the finished job.
Both these pictures were taken in April 2009 when the pond was made.
The ‘after’ picture below is from 4 Jan 2010 – the turves are growing well and holding down the liner.
So for the edge of the pond we’ve worked out a reasonable solution.
But inside the pond is still a bit of a mess – we haven’t rushed to cover it in plants (one way of hiding the liner) but we haven’t quite yet worked out a good way to get sand and gravel to stay in place on the gently sloping smooth butyl. Of course this isn’t a problem when you dig into natural clay, sand or gravel – but it’s a key issue with a synthetic liner: how to get a natural substrate anywhere except where the liner is absolutely level.
Any ideas much appreciated!
