Controlled release fertilizers (CRF) provide nutrients that dissolve gradually, remaining available to plants longer than conventional fertilizers. This study investigates the influence of phosphate glass and biochar, as prospective controlled-release fertilizers, on the growth and development of rose seedlings. Biochar is the product of thermochemical conversion of biomass, where organic substances are thermally broken down at specific process parameters, in a reduced oxygen atmosphere. Phosphate glass (45.4P₂O₅·25.6K₂O·14.5CaO·3.1SiO₂·9.3MgO·1.2ZnO·0.9MnO) was synthesized from reagent-grade materials by melting at 1230 °C for 1 h in a porcelain crucible and quenching on steel. Different dosages of plum stone biochar (PS) and phosphate glass (PG) were tested on rose plantings. The addition of PS and PG had no significant influence on the number of branches, but higher doses (3 g of PG and 10 g of PS) favored flower formation. Chemical analysis at the end of the cycle showed increased phosphorus and manganese in all samples, higher zinc with 2 g PG, and elevated calcium in all variants. Overall, addition of PG and PSB to the soil samples improved rose growth.