Best way to line the bottom of a raised garden on a balcony?

[OneMansFool]

Hi folks, I recently bought a small raised garden bed (corrugated metal, rectangular, no base). I am setting it up on my balcony and will use it for potted colour, maybe some herbs just for fun, just a spot I can change up occasionally and keep looking nice.

My intention is to (a) line it with a waterproof plastic, so that it doesn’t spill water everywhere and onto my downstairs neighbours, and (b) fill the bottom with some polystyrene to keep the overall soil volume and weight down.

Does this sound like a reasonable plan, and is this product here (Grunt Panda Film) the appropriate thing to use for lining the bottom? I’m thinking I will tape it in place with gorilla tape or similar.

[MitchellMc]

Hi @OneMansFool,

Using the Grunt 3 x 5m 150um Panda Film will waterproof the garden bed for you. I've been using GRUNT 2m x 5m Black 100um Builder's Film Handy Roll for the past year on one of my garden beds, and it has worked perfectly fine. I didn't use tape on mine but laid the plastic in the raised bed and filled the soil on top of it. I then came back and trimmed the excess plastic off flush with the soil. Your tape idea sounds like a good idea, though.

Having the polystyrene in the bottom will be essential as it allows somewhere for the excess water to sit so your soil won't be wet all the time. Remember, if you have a waterproof garden bed exposed to rain, it could fill up with water and become a pond.

Please let me know if you have further questions and keep us updated on your project.

Mitchell