Leachates were produced by washing Hydra-fill, a polyurethane ester foam, with water. These leachates decreased radish (Raphanus sativus L.) and tomato (Lycopersicon esculenturn Mill.) seed germination and were phytotoxic to seedlings. Washing the foam for as little as 5 minutes (compared to not washing) before collecting the leachate significantly decreased the mean seed germination time by 0.6 to 1 day. Rinsing the foam with ethanol before collecting the leachate was detrimental to germination. When used as a potting medium component, the foam reduced radish shoot and root dry weights compared to potting media without foam. Washing the foam with tap water before use resulted in increased radish shoot and root dry weights. Hydra-fill generally reduced plant performance when included in potting media. However, radish grew well in fresh 25% Hydra-fill (raw or washed) mixed with loam.