Topic: Considering a pond

[SpeedyMango]

This is my first post in the 'ponds' section...

We are considering putting in a small wildlife pond at the end of our allotment. Others have done it on our site, so it seems to be acceptable. However....

Would an old domestic cold-water tank make a good pond? Some friends have an old one sitting in their garden that we might be able to use. I was thinking of burying it at the end of the plot, or possibly half-burying it as it'll need quite a big hole!

I am loathe to use a flexible liner as we have some pernicious weeds about (couch grass etc) that I am worried will pierce a liner. Those rigid plastic ponds seem to be quite expensive for what they are.

Would I need to do anything to the water tank other than block any holes? Is it too deep for a wildlife pond? Should I part-fill it with ballast/earth/anything else?

We don't have any small shildren around (yet!) but if it remained a deep pond then I would cover it with a grid or something to prevent anyone (or any animals) falling in.

If it's likely to be too much hassle then we might just save up for a rigid plastic pond liner instead.

I'd be grateful for any tips/encouragement or words of warning!

[Margaret]

Hi Speedy.I would have serious reservations about the tank.Unless it is made of plastic it is not good for water to come into contact with anything else.This is a firm belief i have held for many years,being extremely cautious about what i put into my fish and nature ponds,and the theory seems to hold up.

Secondly,a nature pond really must have a gentle slope out of it for the amphibians.Frogs and newts can certainly jump or slide in but getting out again,which they must be able to do,is just not possible from something like a steep sided tank.

Rigid plastic ponds can be a compromise if you can find something to place onto the provided shelves that the frogs can climb or jump onto before getting out but the only really suitable way is a liner pond.It should have a shallow area leading gently out,and a deeper part for the frogs and newts to overwinter in the mud.It can be made to look far more natural around the edges than any prefabricated pond and indeed the more plants you put in around the edges and behind the pond,the better for the shelter they need and the insects that are attracted there for food.

Which just leaves the problem of the weeds penetrating the liner.Easily solved,this one.Dig your hole,at least 18 ins deep or more if you can.Obviously clear away as many of the weeds as possible.Line it with a good layer of sand.Then place on top,a nice thick piece of old carpet.Make sure it comes up the sides as far as possible.Then place your liner over that.Use a good quality one,which again will help prevent problems.Place a good layer of garden soil in to the bottom,but make sure it has not had fertiliser added.Then run in the water at a gentle pace.

It will look awful for a few days but will settle,then you can start planting up the plants,oxygenating weed etc.You cannot overplant a nature pond.The more you put in,the better chance of keeping the water free from algae.Beg a bucket or two from another pondie to get some insect life going.then stand back,and wait!! It shouldn't be long before you are rewarded with slug control!!

Don't be tempted to put a cover or grid over as this may prevent any hedgehogs getting out.If there were to be a risk from small children then a fence around it would be better.

[SpeedyMango]

Thanks for that, Margaret. Very good advice!

Will carpet and sand really stop roots though? I  found a couch grass root growing through one of my onions the other day! I would hate to invest in a pond liner and then have it ruined by an errant root. I will investigate the cost of flexible liners around here.

Probably an easy question to answer if I have a look on the internet, but what plants would be a good start for a wildlife pond?

[Margaret]

I'm in the lounge if you want to chat!!

[Deleted]

I've got a rigid pond in my garden (see post/pics earlier today; http://www.allotments4all.co.uk/yabbse/index.php/topic,10905.0.html ). There's no problem of the weeds that you have of course, so I wish I'd had a flexible liner - I keep changing my ideas :-\.  On the 'frog access' front, it has a shallow  6" 'trough' all the way round which can be planted up and provides great access for the frogs and insects. In my pics I had just done a through thinning of my edge planting, hence the egdes show, but because of this trough it usually blends in well.

[SpeedyMango]

Sorry Margaret, can't chat during the day!

I have had a look at some of the prices of flexible liner, and some places seem to be quite reasonable.

Looks like the project might be a goer - but possibly in the autumn when the rains return, there's not enough water on the site at the moment to justify filling a pond!