Sequential batch leaching tests were used to evaluate the mass of DOC released from composted garden organics (yard waste), pine and hardwood under pseudo-equilibrium conditions. All media showed an initial rapid decline in DOC values followed by a slower rate during later time periods. Greater than 50% of the DOC leached occurred within the initial time period (< 24 h). The mass of DOC leached varied significantly between the materials and to a lesser degree between different particle size ranges. The pine had the lowest leached DOC fraction (2.8-4.8 mg/g), while the hardwood (21-27 mg/g) and compost (13.6-32.7 mg/g) were significantly greater. The type and processing of the woody material incorporated into these systems can have a significant impact on the treated stormwater. (c) 2008 Elsevier Ltd. All rights reserved.