Biodegradable additives are required to minimize the environmental hazards from drilling fluid wastes. This study explores the feasibility of the applications of henna leaf extracts (HLE) and hibiscus leaf extracts (HBLE) as ecological benign products in water-based drilling fluids (WBDFs). Rheological and filtration characterizations were carried out on the WBDFs to detect the effects of different concentrations (1, 2, 10, 20, 30, and 40 g) of these plant extracts at 78 and 300 °F. The results of 1 and 2 g of the plant extracts were compared with those of low-viscosity polyanionic cellulose (PAC LV). Compatibility test was carried out using 25 g/L of the green additives on base fluid (A-0), and the swelling rate of sodium bentonite in distilled water was also considered using 1, 10, and 20 g of the green additives. The findings showed that HLE and HBLE significantly reduced the filtrate loss between 62% and 67% and between 64% and 76%, respectively, and improved the rheological characteristics of the WBDF system between 10 and 40 g. PAC LV showed a greater effect on the rheological properties than the green additives in equal amounts (1 and 2 g), but it exhibited flat high and progressive gels which can lead to mechanical pipe sticking. The test data also showed that the inclusion of HLE and HBLE in the WBDF demonstrated larger impact on the mud cake than PAC LV. The cake thickness of the WBDF was reduced in the following order: 30–32% (by HLE), 32–33% (by HBLE), and 24–27% (by PAC LV). This interprets the outstanding filtration characteristics of green additives. Further, compatibility test data confirmed that the green additives are compatible with the other base fluid additives and the swelling behavior of sodium bentonite verified that the green plants are effective in inhibiting bentonite swelling. Here, the Henna extracts displayed higher inhibition property than the Hibiscus product. Notwithstanding, both products showed excellent inhibition property and a strong viscosity enhancing effect on the WBDF system.