Lime is one of the oldest construction material and it shows greater durability properties. The main aim of the study is to analyse the organic modified lime mortars used as bedding and plastering mortar at Sacred Groves, Auroville Pondicherry, India. Locally available organics namely kadukai (Terminalia chebula) and jaggery (Unrefined sugar) were used to alter the properties of lime based mortars as added by ancestors in traditional buildings. Organics on fermentation reduce to carbon - di - oxide and enhances the formation of calcite and alters the hydrated phases and mechanical properties of lime mortar. Lime and quarry dust in the ratio of 1:3 with fermented herbal extract were casted and tested for compressive, flexural strength. Organic modified mortars shown better performance than reference mortars. Analytical techniques XRD, FESEM with EDX and FT-IR were undergone to study hydrated phases, morphology and presence of organics. © 2019, RILEM.