An experiment was carried out on potted grafted tea in a greenhouse to quantify the effects of reducing soil moisture content on key physiological factors affecting growth, development, diurnal and physiological responses among tea composite clones as affected by varying water conditions. The reduced soil moisture content reduced the leaf water potential in all the clones. The diurnal differences in leaf water potential were more pronounced at the 12.5% v/v soil moisture content. Generally, the mean leaf water potential increased with a decline in soil moisture content. Based on this study, the minimum moisture level below which composite tea plants might suffer water stress is below 30% v/v, and the exposure period should be short. Rootstocks identified as being potential for commercialisation are TRFK 57/15, TRFK 8/112, TRFCA SFS 150 and EPK TN 14-3. Among the Scions, AHP S15/10 was found to be more susceptible to water stress. Relative water content declined with decrease in soil moisture content (R2=0.9915, P≤0.001) in all the scions. The total chlorophyll content varied between clones and decreased significantly (P≤0.05) with increase in soil moisture content. Rootstocks did not affect the chlorophyll content. The differences in chlorophyll between clones could significantly reduce the photosynthetic capacity. The leaf water potentials, relative water content and chlorophyll contents can be used as water stress indicators in composite tea.