Background <p><i>Salvia substolonifera</i>, an important ornamental and medicinal plant that flowering in early spring, relies on seeds for sexual reproduction to sustain its population. Furthermore, the role of mucilage produced when its seeds are exposed to water under different environmental conditions, as well as artificial propagation techniques, remain unclear. We hypothesize that mucilage plays a crucial role in promoting germination under different environmental conditions.</p> Methods <p>In this study, we systematically compared the germination percentage, germination index, and mean germination time under different temperatures and light, water potential, and pH on seed germination in the presence and removal of mucilage in <i>S. substolonifera</i>. Additionally, the effects of exogenous GA₃ at different concentrations on seed germination were also evaluated.</p> Results <p>Our results show that under different temperature, light, and water potential conditions, the presence of mucilage promotes seed germination percentage and germination index, and shortened the mean germination time in <i>S. substolonifera</i>. Interestingly, germination percentage was higher in the presence of mucilage than in mucilage removal under acidic to neutral pH and vice versa under neutral to alkaline conditions. Additionally, the optimal germination temperature was 20–30 °C with 12&#xa0;h of light in <i>S. substolonifera</i>. A concentration of 200&#xa0;mg/L GA₃ was found to be optimal for promoting germination, increasing the germination from 67.5% to 87%.</p> Conclusions <p>These results provide new perspectives for further understanding the ecological functions of mucilage and lay the foundation for seedling establishment and large-scale production of <i>S. substolonifera</i>.</p>