Too thin = weeds punch through in weeks. Too thick = anaerobic decomposition kills soil life. There's an exact sweet spot.
Properly built sheet mulch beds retain 3x more moisture than bare soil, cutting irrigation needs by 55-65% in NC summers.
A 2-inch overlap blocks light completely. Gaps as small as half an inch let weeds colonize the entire bed within a month.
Dry cardboard repels water and resists decomposition. Pre-soaking for 24 hours activates microbial colonization and ensures even breakdown.
The calculator outputs exact cardboard sq ft, overlap specs, compost depth, and mulch volume based on your bed dimensions.
Sheet mulching inverts the weed-feeding cycle. No tilling. No dormant seed germination. No fungal network destruction.