ABSTRACTMycotoxins produced by severalFusariumspecies have a significant effect on reducing maize yield and grain quality and have led to food safety concerns. The antifungal activities of rooibos (Aspalathus linearis) and honeybush (Cyclopiaspecies) tea extracts reduced the growth of plant pathogenBotrytis cinerea, but their efficacy againstFusariumspp. is unknown. In this study, we examined the effects of fermented and unfermented rooibos (A. linearis) and honeybush (Cyclopia subternata) aqueous extracts as well as green tea (Camellia sinensis) against 10Fusariumspecies. Conidial viability was assessed by fluorescence microscopy dyes, ATP production was determined using the BacTiter-Glo assay, the mode of action was analyzed by scanning electron microscopy (SEM), and quantification of polyphenols was done using high-performance liquid chromatography with diode array detection (HPLC-DAD). Fermented rooibos extract demonstrated the highest antifungal activity (P< 0.0001) againstFusarium verticillioidesMRC 826-E,Fusarium subglutinansMRC 8553,Fusarium proliferatumMRC 8549, andFusarium globosumMRC 6647, with only 9.53%, 9.26%, 11.0%, and 12.7% ATP production, respectively, followed by antifungal activity of the fermentedC. subternataextract againstF. subglutinansMRC 8553,F. subglutinansMRC 8554,F. proliferatumMRC 8550, andF. verticillioidesMRC 826-E with 3.79%, 6.04%, 6.04%, and 8.40% ATP production, respectively. Extract-treated conidia examined by SEM exhibited disruption of conidial hyphae and collapsed spores. Overall, the fermented rooibos andC. subternataextracts showed higher antifungal activity against theFusariumspecies than the unfermented extracts.IMPORTANCEIn maize subsistence farming areas in South Africa, daily consumption of maize contaminated by high level of mycotoxins contributes to long-term health effects such as immune deficiency and cancer. Biocontrol methods that are safe and cost-effective are critical to addressing this public health problem. Plant extracts known as biocides or green pesticides are alternatives to chemical pesticides due to their safety and eco-friendly properties. In South Africa, rooibos (Aspalathus linearis) and honeybush (Cyclopiaspecies) contain polyphenols with significant antioxidant and antimicrobial properties. These indigenous herbal teas are widely available and consumed in South Africa and have potential as an innovative approach to reduce mycotoxin levels and, subsequently, human and animal exposure to these toxins. This study evaluates the efficacy of the antifungal activities of several aqueous extracts prepared from fermented and unfermented rooibos (A. linearis), honeybush (Cyclopia subternata), and green tea (Camellia sinensis) on 10Fusariumstrains.