Concrete raised beds

adrianjeavons74

I have recently built a couple of raised beds out of concrete blocks which will be rendered. My question is in terms of finishing them off for planting:
1. Inside the raised beds do you put a membrane at the bottom and up the sides then fill with soil to your level? 

2. I’ve also heard some say that you should drill holes near the bottom to allow for water to escape?

Thanks

Adrian

nick615

If you'd built it out of timber in some form, then a membrane would be advisable, but not really necessary for concrete.  If there's any risk of existing weeds reappearing, the general consensus is to beg some heavy cardboard from a white goods shop (from fridges, washing machines etc.) and lay it several layers thick all over the bottom.  That will scupper the weeds but still permit drainage.  If you did choose membrane and didn't punch holes in it, a good downpour of rain would create a soggy mess.