The goal of this study was to assess the influence of the growth substratum structure on growth and development in Cotoneaster dammeri “Skogholm” saplings during the first vegetation stages. The large share of garden soil (50-60% of the volume) and of peat (30%) had a negative influence on some biometric and physiological parameters of the saplings through the correlation coefficient (leaf area – LA, r = -0.940; sapling height – H, r = -0.922; sapling diameter – D, r = -0.976). Increasing the share of sand in the mixture (40-50%) had a positive influence on the same biometric and physiological parameters (LA, r = 0.927; H, r = 0.899; D, r = 0.971). Between physiological parameters at leaf level that evolved in direct relationship with the growth substratum, were identified statistically ensured interdependence relations (leaf length – leaf area, R2 = 0.993; p<< 0.001; leaf width – leaf area, R2 = 0.984; p<< 0.001; leaf number – leaf area, R2 = 0.991; p<< 0.001). Based on the photosynthetic area of each variant, the saplings accumulated differently the biomass at stem level, in correlation with the leaf area resulted from the number of leaves and their size (LA – H, R2 = 0.932; p<< 0.001; LA – D, R2 = 0.978; p<< 0.001).