This study was conducted to determine the effect of N:P:K fertilization and some bacterial species on the flowering and development of Hyacinthus orientalis cv. 'Delft Blue' plant. In the study carried out under laboratory conditions according to randomized plot experiment design, full and half (1/2) dose of 20:20:20 N:P:K commercial fertilizer was applied to hyacinth bulbs as inorganic fertilizer. Nitrogen-fixing bacteria: Cellulomonas turbata (TV54A), phosphate solubilizing bacteria: Bacillus-GC Group (TV119E) and nitrogen-fixing and phosphate solubilizing bacteria: Kluyvera cryocrescens (TV113C) and TV54A and TV119E bacteria types were used as biological fertilizers. In the study in which some phenological and morphological observations were made, the earliest time of first flowering, full flowering and harvesting were determined as 52.07, 53.70 and 54.66 days in 1/2 N:P:K application and the difference between the applications was found to be statistically significant (P<0.001). Bacterial applications caused a ten-day delay. The highest leaf width average (24.43 mm) was obtained in TV119E application (P<0.01). The maximum number of leaves was 7.13 (1/2 N:P:K), leaf length was 245.57 mm (TV113C) and plant height was 364.24 mm (TV119E). It was found that bacteria prolong the flowering start times, that is, N:P:K fertilization makes flowers bloom in a shorter time. In addition, leaf growth and bacterial inoculation of the plant were determined to be effective.