Abstract: After research which identified waxy cuticular pits as organs of floatation in Watermeal (Wolffia columbiana), this study examined the use of detergents for control by disruption of floatation. In addition to disruption of floatation, treatment with the detergent Tween 20 dramatically increased the infection of plants by natural fungi. Most Wolffia plants grown under conditions similar to natural conditions formed clumps, sank and died within 5 days when exposed to 0.1% Tween 20 by a combined mechanism of chemical and biological control. This study describes a method for control of Watermeal which depends on enabling natural fungi to opportunistically attack these plants, once their floatation is disrupted by low concentrations of relatively non-toxic detergents. This method may be developed to use low toxicity detergents as a method of control for floating nuisance plants in urban environments.