Polyploidy (multiple copies of whole genomes) is over-represented in invasive plants and thought to promote their success in novel environments. Understanding functional traits supporting colonization can provide a foundation for development of effective management strategies. In a new study published in AoB PLANTS, Grewell et al. compared how two aquatic invasive congeners differing in ploidy (diploid, decaploid) respond to resource availability (light, nutrients). Counter to their predictions, the diploid congener out-performed the decaploid with nutrient enrichment. Their results suggest the congeners have alternate colonization strategies, and that trait responses underlying their success may change with ontogeny. Management strategies for invasive Ludwigia species should therefore be tailored for specific cytotypes and unique characteristics of their life stages.