A long-term study was carried out at the Herzen State Pedagogical University’s Biological Research Station in the Leningrad Region, Russia. The article presents the data analysis aimed at selecting efficient associative strains for a variety of economically valuable Brassicaceae plants. The selected strains increase plant biomass. The best results are obtained when using the following bacterial preparations: mizorin (Arthrobacter mysorens, strain 7) and flavobacterin (Flavobacterium sp., strain L 30).