Planter/slats question

[MrsGuyOfGisbo]

Bought some wooden planters to go against the walls as DH hates stuff attached to house wall. but the bottom is wooden slats - numpty newbie question, but how do I keep the earth in... there are plastic liner things in homebase, but different size to the planters.

Can you get lengths of shade cloth and cut to size? I ask this because it's easy to get in Au. It will hold the soil in while allowing drainage. Cut up wool blankets will do the same - cheap as from charity shops.

Thanks, that's is great idea! Also, thinking about it, apparently slugs hate wool, so could be two birds (so to speak ) with one stone.