Building a pond amongst trees

[GoldenWattle]

I'd like to have a pond. I even went so far as to clear an area big enough for me to dig a reasonably sized pond. I pulled up and potted a blood orange tree (which I suspect is on Flying Dragon rootstock and suitable for potting) and removed some lavender and pineapple sage. The issue is that the area is on a slope and between a melia azedarach (top) and a large gum (bottom). I was initially going to buy pond liner, but it occured to me that invasive roots might pierce the liner. I was wondering if anyone knows if the fibreglass (covered in sand) would be durable enough to stop invasive roots. I also considered digging a trench and then concreting. I don't know how thick the concrete would need to be. Is there a solution to my problem or am I better off not attempting to build a pond?

Cheers,
GoldenWattle

[ColinM]

Hi GW,

A tricky situation. Firstly, I guess, at the end of the day it depends on how invasive the remaining trees are and how close their roots are to your intended pond.

Not sure on your liners over there, but the stuff over here wouldn't take much to punch a hole in.

IF, I was going to attempt that, I would probably go concrete with reo (reinforced mesh).

But hard to say without being there.

The other consideration of course is how much debri will be dropped by the trees (leaf littler) and the like as you'd want to minise that or at least keep it to a level that's easilily managed with a net.

Finally, if you intend to grow water lillies, then you don't want continuous shade - I believe 4-6 hours direct sunlight min is recommended. I put shade cloth over our pond as my wife wanted ferns and the like around it and now our lillies look a lot sadder and won't flower

[karyn]

10 years ago i dug 2 ponds at Mums, under gums. We lined them with newspapers, about 3 newspapers thick and used doubled over black plastic. One of them sprung a leak this year so I think 10 years is pretty good going! We clean them out thoroughly every 2 years or so, hard work to lift all the stones etc. They don't have filters or pumps, so get stagnant if not refreshed with clean water every noiw and then. If I was to do it again, I'd use a pump and recirculate the water.

[ColinM]

Hi Karyn!

The plastic liner over here is rated for 10 years anyway, so that's good going!