Abstract: Background and Objectives: The use of bio-fertilizer is a safe and economical method for increasing soil agricultural fertility and productivity rather than the conventional use of chemical fertilizer. Hence, this study was conducted to investigate the biofertilizer potential of Chlorella vulgaris, nitrogen, phosphorus and potassium (NPK) fertilizer and poultry manure on the microbiological and physico-chemical characteristics of the rhizospheres soil of Hibiscus esculentus at 2nd, 4th and 6th week of growth. The effect on germination, biometric and biochemical constituent of the plant at maturity was investigated and the best method of application of Chlorella vulgaris (bio-fertilizer) was determined. Materials and Methods: Disease free okra seeds were obtained from a market within Port Harcourt metropolis. They were inoculated with Chlorella vulgaris, NPK fertilizer, poultry manure and monitored for 6 weeks. Plant height, leaf count and fresh weight of the plants were determined alongside with microbiological and soil physico-chemical analyses. Obtained data were statistically analysed by one-way analysis of variance ANOVA using SPSS. Results: The results showed significant difference in the microbiological and physico-chemical constituent of the rhizospheres soil for all the treatment given and the bulk soil, bacteria count ranged from 3×108-30×109 CFU g–1 while fungal count ranged from 5×104-90×106 CFU g–1, nitrogen content ranged from 0.15-0.99%, organic matter ranged from 2.95-8.67% potassium content ranged from 9-16.75 mg/100 mL and phosphorus ranged from 5.09-15.9 mg/100 mL. The combined seed and soil inoculation of Chlorella vulgaris speed up germination of the Hibiscus esculentus and its maturity at 3 days and 8 weeks, respectively. Highest pod yield and plant height were obtained in combined seed and soil inoculation with Chlorella vulgaris. Conclusion: Chlorella vulgaris (bio-fertilizer) is efficient and economical in improving soil nutrients for greater productivity of Hibiscus esculentus.