The relationships between trait plasticity and canalization, and between phenotypic integration and plasticity, have been under debate, largely because direct evidence is still scarce for their associations, especially in response to environments. To investigate the relationships between canalization, integration and phenotypic plasticity in response to emergence time, we conducted a field experiment with an annual herbaceous species of Abutilon theophrasti, by subjecting plants to four treatments of emergence time (spring, late spring, summer and late summer), to measure a number of morphological traits and analyze correlations of plasticity with canalization and integration in these traits, at two stages of plant growth. Results showed plants with delayed emergence had higher phenotypic integration and more positive correlations between integration and plasticity, but less negative correlations between decreased canalization and plasticity, compared to those emerged in spring. Results suggested significant environmental changes that induce plastic responses, rather than environmental stress, can result in greater phenotypic integration in plants. Negative correlations between decreased canalization and plasticity occurred more frequently in plants emerging in spring and the least frequently in those emerging in summer, suggesting their relationship depends on specific environmental conditions and the degree of plasticity. Both increased phenotypic integration and decreased canalization might merely be the outcome of plastic responses, rather than mechanisms constraining or facilitating plasticity.