The increase in salinity of water resources is a major challenge in agricultural production, particularly in arid and semi-arid regions, limiting plant growth and yield. This study aimed to investigate the interactive effects of potassium silicate (K₂SiO₃) and salinity stress on growth, physiological-biochemical parameters, and ionic balance of Plumbago auriculata plants, as a species possessing salt glands, under greenhouse conditions. The experiment was conducted as a factorial arrangement in a completely randomized design with three replications. Treatments included three salinity levels (0, 50, and 100 mM NaCl) and three potassium silicate concentrations (0, 4, and 8 mM) applied as foliar sprays. Results indicated that salinity stress significantly reduced plant height and adversely affected physiological and biochemical traits, leading to decreased phenolic compounds, flavonoids, and soluble sugars, while increasing oxidative damage (malondialdehyde, MDA accumulation) and sodium content in leaves. Application of 8 mM potassium silicate under 100 mM salinity increased plant height by 33% compared to the control, indicating amelioration of salinity-induced growth inhibition and improved plant performance. Moreover, potassium silicate enhanced antioxidant capacity by increasing phenolic and flavonoid compounds (particularly at 4 mM concentration) and soluble sugars, while improving ionic balance through increased potassium uptake and reduced sodium accumulation, suggesting its role in mitigating oxidative stress and maintaining membrane integrity. Overall, potassium silicate demonstrates potential for improving salt tolerance in P. auriculata under controlled conditions; however, confirmation of its practical efficacy in urban landscape settings requires further field studie