Organic matter mulches are an important multi-purpose tool in organic agriculture. Mulches suppress weeds by competing for sunlight, moisture, and nutrients. Mulches also improve soil health by reducing erosion and increasing soil organic matter. For crops such as muskmelon and squash, mulches protect fruit from moist soil that contributes to fruit rot. The goals of this trial were to compare the abilities of two mulch treatments to suppress weeds, to increase soil organic matter, and increase marketable yield in organic muskmelon and acorn squash.