Wooden trough planter - how to stop rotting?

waterwatereverywhere

Hi,

We're about to plant a large wooden trough. The wood probably was once pressure treated but it's now an old trough - can we line it with some of that thick black damp proof membrane and then fill with compost? We have a roll of this stuff left over from some building works so it would be great to use that and not have to buy special gardening stuff but it is pretty thick strong stuff and prob. not breathable.

Would it be okay to use provided we make holes in it for drainage at the bottom?

Many thanks for any help on this.

[Deleted User]

My OH has just made some wood troughs for me out of pressure treated wood. I want them to last as near forever as possible so they have been painted with wood preservative paint as well.

Joly_Roger

This answer is probably too late, but yes, damp proof membrane, or vapour barrier would be perfect.

I just did the same thing with some home made timber window boxes, using some spare vapour barrier from a bit of plasterboarding/insulating I was doing.

You've already treated the wood, so I'd advise you to:

Drill small drainage holes in the bottom of the trough, then put a small layer of gravel around the holes, & then add the liner, trimming any excess liner around the sides.

Then puncture holes at the bottom of the liner (ideally close to where the darinage holes in the trough are) so excess water can drip out.

The gravel will act as a sump, directing excess water to the drainage holes, so that your timber trough doesn't become damp and rotten.


The above method seems to work fine with me & the liner helps to prevent evaporation, thus reducing the frequency of watering required.

savemoney

Maybe pond lining like EPDM which the also use on roofs

laurel7172

I have some 17 year old troughs I've just renovated. The basic structure was sound.

Yes, I've always kept them lined with plastic, and I've emptied them completely at least every couple of years to treat with preservative inside and out. For all that they were built with pressure treated timber, it really doesn't seem to penetrate very far, so cuts need special attention. To the extent that I've had to replace timber, that seems to have been the problem. And I've kept them standing on bricks-not in contact with the ground.