Hello. Just to say straight away, I’m not a gardener in any way! I am in the process of putting some treated timber flower beds down. I was just wondering if I can put down weed membrane on the grass (I didn’t dig it up before laying the timber. Hindsight and all that), and then putting top soil on top of the membrane or do I need to remove the grass that’s there? Any tips would be appreciated. Thanks in advance.