He Put Cardboard Right Over His Grass Before Building a Garden Bed
Removing sod can turn a new garden bed into a digging project before any soil or mulch goes down. One homeowner skipped that step and left the existing lawn where it was, even though the grass covered the full area he wanted to change.
TikTok creator Brandon Gentry (@brandontgentry) wanted a flower bed around a river-rock area in his front yard without digging out the sod. His solution started with flattened cardboard boxes placed right over the grass.
Cardboard isn’t there as a permanent landscape barrier. It blocks light from reaching the grass and weeds below while the material softens and breaks down under the new bed. That lets the existing lawn die beneath the surface rather than requiring it to be cut out first.
Existing Grass Stayed in Place
Gentry marked out a curved bed beside the house and around the existing river-rock area. Sod still covered the space, including the sections running against the lawn and around the evergreen.
Instead of removing that layer, he used it as the base for what came next.
Flattened Boxes Covered the Grass
Cardboard boxes were opened flat and spread across the planned bed, with pieces overlapping rather than stopping edge to edge. Bags of material helped hold them down while more cardboard was positioned around the curves.
Overlap matters here because exposed gaps can give surviving grass and weeds a path through the new bed.
Water Soaked the Cardboard Before It Was Covered
Once the cardboard covered the grass, Gentry saturated it with a garden hose. Wet cardboard conforms to the ground, stays in place, and starts softening before soil and mulch go on top.
The grass underneath is now separated from sunlight by a continuous layer rather than being removed with a shovel.
Cardboard Disappeared Under the New Bed
From above, the flattened boxes cover almost the entire planting area while the river rocks remain exposed. Their printed surfaces look temporary because they are: cardboard is meant to decompose rather than remain under the bed like plastic.
Once buried, the boxes become the hidden layer between the old lawn and the material above.
Mulch Covered What Used to Be Lawn
Finished sections show no cardboard or exposed sod. Brown mulch follows the curved edge beside the rock bed, covering the same ground that held grass at the start.
That is the point of putting cardboard underneath: it smothers the existing lawn while allowing the bed to be built without stripping away the sod first. As the cardboard breaks down, it stops acting as a separate layer.
The Grass Was Still Under There
Dark mulch finishes another section of the bed, leaving no sign of the cardboard boxes beneath it. The original lawn was never hauled away; it was covered and left below the new layers.
Gentry later shared an update showing flowers growing in the bed without grass taking it back over. Would you trust cardboard to kill the lawn underneath, or would you still dig out the sod first?
Image credits go to @brandontgentry.