Field Guide · Soil & compost · 7 min read

How to Sheet Mulch a New Garden Bed

Cardboard, compost and wood chips turn lawn into a garden bed without digging up any sod.

Written on the farm by Nathan Story · Story Thyme Farms, Missouri · Updated

Story Thyme Farms · Bench cardFall for spring beds

Sheet mulching a new bed

Building a bed in layers over living grass

DifficultyHeavy but simple
Cardboard overlap6" minimum
Layers2" compost, 3–4" mulch
ReadyPlant through anytime
1Preparing the groundMow it short, then feed the soil
2Laying the cardboardOverlap plain brown cardboard by six inches
3Adding the layersCompost first, then a thick layer of carbon
4Planting into itYou can plant through it whenever you want
Materials needed · Cardboard (free) · Compost · Straw bales · Digging fork
Written on the farm · Missouristorythymefarms.com/guides/how-to-sheet-mulch-a-garden-bed

Prints on one page. The long version below stays on the screen.

The long version

Watercolor cross-section of a sheet mulched bed, grass under cardboard under compost and chips
Building a bed in layers over living grass · field plate

Sheet mulching kills lawn the same way a fallen log does: it blocks the light, holds moisture, and lets soil life eat everything from underneath. There is no tilling, no herbicide and no sod to haul away, and worms do the work of mixing it in. Build it in fall and you will have a bed of dark crumbly soil by spring.

  1. Step 1 · Preparing the ground

    Mow it short, then feed the soil

    Watercolour plate of a patch of lawn mowed down to the scalp with clippings left lying, a digging fork stabbed in to relieve compaction

    Mow the area as short as the mower will go and leave the clippings where they fall. If the soil is compacted, push a digging fork in every foot or so and rock it back and forth to crack the soil open, without turning it over. A scattering of compost or manure straight onto the grass gives the decomposers a head start.

  2. Step 2 · Laying the cardboard

    Overlap plain brown cardboard by six inches

    Watercolour plate of sheets of plain brown corrugated cardboard laid across a bed with seams overlapping generously, tape stripped off

    Pull the tape and staples off plain corrugated cardboard and lay it over the whole bed, overlapping the seams by a full six inches, because grass will find any gap. Then soak it thoroughly with a hose. Wet cardboard lies flat against the ground, feeds fungi, and stays in place while you build on top of it.

  3. Step 3 · Adding the layers

    Compost first, then a thick layer of carbon

    Watercolour plate of the cut edge of a newly sheet-mulched garden bed in four stacked bands, from the bottom upward: green lawn grass at the very bottom, then a sheet of plain brown corrugated cardboard laid flat over the grass, then a band of dark crumbly compost, and coarse pale wood chips as the topmost layer

    Put two inches of compost or aged manure over the cardboard, then three to four inches of carbon material on top of that: wood chips for perennial beds and paths, or straw and shredded leaves for vegetable beds. Water each layer as you lay it down. The whole thing settles to about half its height over winter, so build it generously.

  4. Step 4 · Planting into it

    You can plant through it whenever you want

    Watercolour plate of a transplant being set through an X cut in softened cardboard, mulch parted around it

    To plant in spring, part the mulch, cut an X through the softened cardboard, and set transplants into the soil underneath with a trowel of compost. If you cannot wait, the same trick works right away for large transplants like tomatoes and squash. Small-seeded crops like carrots should wait a season, until the layers have broken down into soil.

Materials needed
Cardboard (free)CompostStraw balesDigging fork

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Questions we actually get

Will Bermuda grass or bindweed die under cardboard?
The honest answer: mostly, not entirely. The running thugs travel until they find an edge. For those, double the cardboard, widen the bed's border past the infestation, and patrol the perimeter the first summer, pulling escapees while they're weak.
Is cardboard ink or glue a problem in a food garden?
Plain brown boxes with black or simple ink are fine, modern inks are soy-based and corrugated glue is starch. Skip glossy coated boxes, plastic tape, and anything waxed. When in doubt, it burns or it composts, waxed board does neither cleanly.
Can I skip the cardboard and just pile mulch deep?
Over weak lawn, eight-plus inches of chips alone can do it. Over vigorous sod, skipping the light-block layer means grass in your new bed by July. Cardboard is free, use it.