[dan808]

Im thinking off laying some tarpaulin down on my allotment  to kill off the weeds does it have to be black or a specific thickness ??  and i was  also going to lay some cardboard down first if it makes a difference.

[Jamrock]

You don't need both, a double layer of standard brown cardboard is sufficient to put most top growth to the sword. Weigh it down with stones or parts of bricks and slabs


I would recommend digging out any perennial weeds, docks especially, before you lay anything though else you are just delaying the inevitable.