[Woodhousemoor]

So I decided to try my hand at DIY today and made a wooden planter to plant excess potatoes in it's 5ft X 2.5ft. What can I use to line it with so I can fill it with compost please any suggestions

[mumofstig]

I use the plastic compost bags to line my wooden flower planters...Overlapped where necessary....don't forget a few drainage holes

[arugula]

Seconded.

[Epona_4]

thirded!

[Woodhousemoor]

Thanks for your useful information this will come in handy for a smaller container .however i don't have any compost bag large enough to fit the planter is there another alternative.

[mumofstig]

You don't have to have one big enough....use as many as you need, and overlap them.

[arugula]

We converted our old 6 x 4 trailer into a planting container and lined it with a pre-loved decorators plastic dustsheet.

[Woodhousemoor]

Thanks, I made a smaller Planter today and the idea of the compost bags worked a treat, but for the bigger one I think I will use some of the polythene plastic I bought for making small poly-tunnels it's clear so hope that wouldn't be a problem.

[jimthejimjim]

I have made quite a few planters myslef and I have never bothered to line any of them.

I don't expect them to last forever and I always use scrap wood from my firewood pile.

[cooperman]

ive used the heavy duty woven ground control fabric bought by the metre, its plastic, lasts for years, permeable so no holes required... it only costs about £1.50 a metre and is 2m wide...

[mumofstig]

If it's permeable, what would be the point in using it to line the planter, as It wouldn't protect the wood at all 

[bigben]

If it's permeable, what would be the point in using it to line the planter, as It wouldn't protect the wood at all 

I would be interested to know if waterproof plastic will do much to protect the wood. Water will find its way down between the plastic and the wood and will be trapped there anyway leading to the wood being fairly constantly wet anyway. The benefit might come from not having the soil organisms in direct contact with the wood so they do not have a direct composting action on it.
It might be an interesting experiment to compare a permeable weed fabric with a non permeable plastic. I suspect the main use for dampproof membrane is to prevent water coming up thru the wall.

[mumofstig]

I suspect the main use for dampproof membrane is to prevent water coming up thru the wall.

That is pretty obvious, but I'm not sure what you mean with that comment 

[bigben]

Having dampproof membrane stops water coming up the porus brick -so has a benefit, it is easy to think the same principle can be applied when in fact the movement of the water is the other way. Putting it into a planter will lead to water getting down the side and being trapped between the plastic and wood so I am unsure if it will benefit other than the protection from the composting action of the soil itself. This might still make it worthwhile but at I suggested it might be interesting to compare with weed fabric.