Mulch calculator

Use about 3 inches for bark or screened mulch and 3 to 4 inches for coarse wood chips. Count the mulch already there so the finished layer does not become too deep.

Usually no. Loosen the existing layer and measure its remaining depth, then add only enough to restore the target; remove material when it is matted, contaminated, or already too deep.

Yes. Pull or treat established weeds first, because mulch is best at slowing new weed seeds, not eliminating perennial weeds already growing through the bed.

Usually skip fabric beneath organic mulch in planted beds. Weeds can grow in mulch above it, and roots can grow into it; permeable fabric is more useful beneath stone or in paths that will not be replanted.

Add mulch when the existing layer has broken down below the depth you want, not automatically every year. Bark often lasts 2 to 4 years and wood chips about 1 to 2 years, so measure the remaining layer before ordering.