Studies on the physical properties of various horticultural substrates such as: bark, perlit, peat, peat + bark (1:1), peat + perlit (1:1), peat + bark + polyamide PA-6 (1:1:1), with added hydrogels such as: Akrygel RP and Alcosorb 400, have been carried out. The influence of the substrate properties with hydrogels added was compared to the control combinations without hydrogels. The following properties were determined in the study combinations: total content of organic matter, substrate reaction, volumetric density, specific surface, porosity and percentage of solid phase. Air and water properties and water-air ratio were determined by means of the pF curve. Applicability of superabsorbents as components of horticultural substrates was also evaluated. In all the studied substrates a more favourable structure was achieved after hydrogel has been added. Alcosorb 400 and Akrygel RP introduced to the substrates has positively influenced their physical properties, considerably increasing retention of water available for plants. They also caused an increase in the specific surface especially in the substrate with perlit and an increase in the pH value in the mixture of peat and bark and peat and perlit. An increase in the applied hydrogel doses from 2 to 6 kg m-3 of the substrate improved substrate properties when compared to the control combinations where superabsorbents were not applied. The results obtained showed that it is feasible to apply hydrogels as additions to horticultural substrates as the effects achieved proved that the most favourable conditions for plant development and growth can be created in that way.