A plant life-cycle bioassay using Arabidopsis thaliana (L.) Heynh. was developed to detect potential chemical phytotoxicity. The bioassay requires large numbers of plants to maximize the probability of detecting deleterious effect and to avoid any bias that could occur if only a few individuals are utilized. Therefore, a culture system was needed which would support large numbers of Arabidopsis and also permit the chemical treatment of either plant roots or foliage. Hydroponic techniques are ideally suited because they allow both root and foliar applications of chemicals. Although various culture techniques have been developed for Arabidopsis, the few hydroponic techniques reported were not designed to support large plant numbers. This paper describes a double-container hydroponic plot culture system. Information on biomass production, moisture and nutrient distribution within the culture system are also discussed.