Why is grass still poking through my sheet mulch?

tinyhomegreen

Sheet mulching isn’t suppressing the grass like it should.
I laid cardboard from the hardware store across the whole bed area, soaked it good with the hose, then piled on wood chips from the tree crew. Grass is still poking through in a few spots after two months.

thesustainist

tinyhomegreen, hardware store cardboard can vary in thickness and sometimes leaves thin spots once the chips settle. Persistent grass like that often needs the cover to stay completely light-proof for longer, or an extra overlapping layer added where it’s breaking through.

tinyhomegreen

The cardboard I got was the thick double-wall stuff they had, overlapped by a good six inches, but the chips have shifted a bit in spots and let some light through. Might try weighting it down more before adding anything else.

compostcadet

chips shifting after rain or wind can open gaps even with solid overlap like that. tinyhomegreen, if the grass keeps coming in those exact spots, tucking in an extra cardboard patch there before weighting might block it without starting over.