Cardboard garden beds cut weed growth by two-thirds, US study finds

A two-year study supported by the USDA has provided evidence that cardboard-based garden beds offer substantial advantages in weed control over conventional tilled beds. The trial found cardboard beds maintained weed coverage at approximately 15 percent, compared to 45 percent in traditionally tilled plots—a reduction of two-thirds.

Weed management remains a critical concern for farmers across regions, as unchecked weed growth can significantly diminish crop productivity. The research demonstrates that implementing cardboard barriers during cultivation can address this challenge while simultaneously reducing the labour intensity associated with manual weeding.

Beyond weed suppression, farmers participating in the trial reported that cardboard beds made subsequent weeding operations considerably more efficient. After two growing seasons of use, the beds continued to deliver these practical benefits, suggesting the approach offers sustained value for agricultural operations.

The trial's findings on crop yields varied depending on the bed type used, indicating that while weed control improvements are consistent, farmers will need to evaluate total productivity outcomes when considering whether to adopt cardboard bed systems. The results add to a growing body of evidence supporting alternative soil management practices that can reduce chemical inputs and labour costs on farms.