Cleome hassleriana Germination in Minnesota Prairies, Roadsides and Gardens

Abstract

Cleome hassleriana is an ornamental garden plant introduced from South America and naturalized in eastern United States with tendencies to reseed primarily in gardens. The objectives of this research were to determine (1) if C. hassleriana cultivars can germinate in Minnesota prairies and roadsides, (2) if germination in cultivated environments reflect germination in non-cultivated environments, and (3) if there are differences among cultivars across environments, with some cultivars germinating well in cultivated habitats and poorly in non-cultivated habitats. In June 2003, 135 seeds from each of four cultivars (Queen Rose, Queen White, Sparkler Rose and Sparkler White) were planted in each of 4 gardens and 8 non-cultivated habitats (4 prairies and 4 roadsides). Germination and survival was recorded once weekly for four weeks. Cleome seeds germinated in Minnesota gardens, prairies and roadsides. By day 14, the proportion of germinated seedlings was significantly greater in gardens (30.5%) than in prairies (1.4%) and roadsides (0.9%). Sparklers had significantly greater germination than Queens in the prairies. The best performing cultivar in the garden (Queen White, 29%) was different than the best performing cultivar in the prairies and roadsides (Sparkler Rose, 1.4% and 1.2% respectively), suggesting that germination in non-cultivated habitats may not reflect germination in the field. Cultivars varied in their ability to germinate in cultivated and non-cultivated environments.