The aim of this work was to use Plant growth promoting rhizobacteria (PGPR) for the improvement of cultivation and agronomic and pathogen protection characteristics of ornamental bulbous plants such as Tulip (fam. Liliacee), Iris (fam. Iridacee), Freesia (fam. Iridacee) and Narcissus (fam. Amarillidacee). The experiments, started in November 2020, were conducted in the greenhouses of CREA-OF in Pescia (Pt), Tuscany, Italy. The experimental groups were: i) group control irrigated with water and substrate previously fertilized; ii) group with Effective microorganisms irrigated with water and substrate previously fertilized; iii) group with beneficial bacteria (TNC Bactorrs13) irrigated with water and substrate previously fertilized; iv) group with beneficial bacteria (Tarantula powder Advanced nutrients ) irrigated with water and substrate previously fertilized. The trial showed a significant improvement in the agronomic parameters analysed on plants obtained from Narcissus, Iris, Tulip and Freesia bulbs treated with microorganisms. In particular, there was an increase in plant height, vegetative and root weight, bulb weight and diameter, and flower duration. In addition, the use of microorganisms in the growing medium showed a significant increase in the biocontrol of Botrytis cinerea. The treatment with Effective microorganisms (EM) showed the most significant results for all agronomic parameters analysed. The improvement in plant growth brought about by the activity of bacteria is a key aspect of achieving sustainable agricultural goals in the future. More research is needed in this field to identify new soil microbial strains that can be used for the formulation of new products applicable for improving the quality and resistance to biotic and abiotic stresses of potted plants.