Topic: soil or not in a wildlife pond?

[suncekoret]

I am currently involved in the construction of a medium/large ( 15m x 8m ) wildlife pond and I am unsure whether it's best to cover the butyl liner with a thin layer of soil or sand to maximize the wildlife and plants. One side is gently sloping and will be covered with paddle stones, other sides are gently sloping or shallow shelves.
Opinions seem to vary in the sources I have studied
Does anyone have practical experience of this?

[grawrc]

Hi Suncekoret and welcome to the site! We built our wildlife pond (about 9' x 6') some 15 years ago. It has a butyl lining. The central area is about 3' deep. 3 sides have shelves for marginals and the 4th is a gentle slope. We put some earth in to protect the butyl liner from the sun. Some plants were just dropped in the water, others are in containers for easy retrieval.

The pond was inhabited (frogs) almost immediately after we put the water in and is still going strong. We have never had problems with it greening up or e.g. blanket weed. It is virtually self maintaining - I just need to thin the plants from time to time and top up the water level occasionally.

[jjt]

 I've thought about this a lot also. There's a lot of pros and cons. Any pond's a wildlife pond really. Soil always ends up in there anyway. Pond plants generally need minimising not maximising, ie they grow strongly. You won't get a thin layer on slopes without a thick layer at the bottom. In a small pond I'd say no soil, that's from experience. But your pond is big.
      Is it supposed to be ornamental as well? Plants in baskets are much easier to manage. But in a pond that size, if it's planted wisely and is going to be looked after at least a bit, you might be better off with soil. I think I'd say none in the bottom. If it's not dug yet then dig it with a lip to the shelves, then you can soil them up. Go for pockets of soil not all over coverage. A lot depends. Situation? Will it end up full of leaves? Maintenance? Will it be looked after?
    As you say, opinions vary. I think a lot of pond books are written by people who just copy out what someone else said. Have a look for good information about pond edging. It all gets amazingly vague and glossed over. "Yeah it's easy, you just do it like that. Like the picture. I won't go into details there's no need". But that's where the devil is isn't it?   
    Some people say put turves in. Think about chemicals if you do that. Who's going to sieve the soil? Not much help I'm sorry. But good luck and remember that in nature ponds end up silting up and disappearing. End up as forests. So don't overdo the soil at any rate.

[GrannieAnnie]

My butyl lined pond is roughly 17 x 24 feet, deepest part is hip deep and has been in place since 2003. I did not put soil in. Quite a lot of debris comes from the air and plants breaking down so you'll have dirt whether you want it or not. The pond has been relatively carefree planted with native water lilies and some pond plants, gold fish and as mentioned the frogs and salamanders just invited themselves and moved in. A great blue heron arrives periodically and cleans out many of the fish and frogs but there are always enough left to repopulate.  I do put in barley straw in old stockings in the Spring and Summer to keep algae down since the pond gets more sun than I'd like but is positioned so we can see it out the window. I bought a bale of barley straw in 2003 and am still using the same bale. It works well and I have no filtration system.

My major mistake was I dug it with  some of the sides sloping instead of flat to maximize the size of the pond. This makes it very slippery in some places. Bad idea. But the pond is the best part of our yard. I hope you enjoy yours, too.