Aim. The purpose of the work is to study the effect of a biological product based on the melaninogenic strain of Bacillus thuringiensis on germination and morphological parameters of highly decorative species of the flora of Belarus, promising for landscaping in the urban environment. Methods. Seed germination in laboratory conditions used  with soaking in solutions of bacterial melanin in concentrations of 0.04, 0.025, 0.01%. Water and Terrasil at a concentration of 0.01 was used for a comparative evaluation of the effectiveness. Results. Morphological parameters were estimated during germination of the seeds of Verbascum thapsus L., Verbascum nigrum L., Centaurea scabiosa L., Betonica officinalis L., Viscaria vulgaris Bernh. treated with various concentrations of the stimulant. Conclusions. The effect of the bacterial melanin on the morphological parameters of plants was species- and dospecific. The optimal concentration for use on the studied plants should include concentrations up to 0.025%. The most pronounced effect of the use of the drug was revealed in the first days of seed germination, which allows the use of bacterial melanin to increase the germination of seedlings. Keywords: bacterial melanin, stimulant, seed germination, highly decorative species of flora.