Gardeners seeking a chemical-free method to control weeds can adopt a simple technique used by professional landscapers: sheet mulching with cardboard. This approach smothers weeds, enriches the soil, and requires minimal effort.
How Sheet Mulching Works
The method involves laying flattened cardboard boxes over weed clusters and covering them with garden mulch. Elizabeth Florio of Garden & Gun explains: "It turns out the cardboard that passes through households in abundance is a low-fuss, good-for-the-soil, sustainable-many-times-over weed barrier." The cardboard blocks light, preventing weed growth, while decomposing to add carbon to the soil.
A gardening enthusiast on the Charles Dowding forum shared success: "Under hedges I put cardboard with wood chip on top, nothing through at all. We also had a weed-ridden border which I put cardboard first, then planted heather into holes cut in it, then put peat compost all over as mulch and it is doing well, heather alive and had to pull about two weeds in two months."
Step-by-Step Guide to Using Cardboard for Weed Control
No need to remove existing weeds before laying cardboard; cutting them back is sufficient. Choose plain brown cardboard with minimal ink and avoid glossy or taped pieces. Pizza boxes are a safe choice. Flatten boxes and overlap them for best coverage. Soak the cardboard with a hose to help it conform to the ground and stay in place.
If planting through the cardboard, cut holes and add compost and planting soil. Otherwise, cover with mulch like wood chips or pine straw. This method is ideal for no-dig gardeners and can keep weeds at bay for months.
