I did first mowing this year, and have extra grass clippings. I would like to use the clippings to cover some areas, currently dominated by grass and weed, where I want to plant and sow some other plants this year, hoping that the clippings will "choke" existing plants and a sort of free the soil for new plants. I gather one feet high layer of clippings would be sufficient for this purpose.
For how long I have to keep the clippings layer until the plants (grass and weed) under that layer are killed, and will not appear again? A month? Three months? A year?
(to clarify more, my intention is not to keep the clippings indefinitely in that area, they will be eventually moved to a compost bin, but not until the plants below the clippings disappear, if that is possible)