[Loopyjump]

Just got my first allotment. Before me, it was left to go to grass and brambles. It was dug up and rotivated. Now I'm there, and loosing the battle against weeds! Have succumb to using round up. My question is this: I covered sections of the allotment in plastic sheeting to limit the weed growth. Should I take that up and let them get kick started again so that they are actively growing before using round up (they are all yellow and struggling at the moment) or just lift the sheeting before I spray round up?

[Sparkyrog]

Roundup works best on fresh new growth ,so I would wait a while