Tea gardens are established on acidic soils (pH < 5.5) and undergo extensive fertilization to maximize yield, which inadvertently promotes the proliferation of various weed species. Commelina communis and Tradescantia fluminensis (Commelinaceae) are major threats to tea plantations causing the highest destruction compared to other weed species. This study investigated the mechanisms behind the tolerance exhibited toward elevated aluminum (Al) concentrations in acidic soils and its contribution to these species' invasive behavior and herbicide resistance. Both species displayed only a 17-22% reduction in biomass under 400 M Al, and the Al accumulation remained low, ranging between 100 and 200 mu g g(-1) DW. Interestingly, C. communis responded to low to moderate Al levels (50-150 mu M Al3+) with growth stimulation. Antioxidant enzyme activity and flavonoid and anthocyanin leaf concentrations increased with Al treatment concentrations. Surprisingly, exposure of plants to Al, particularly at the 50 mu M threshold, resulted in a significant reduction in leaf damage inflicted by a spectrum of herbicides (paraquat, glyphosate, clethodim, and 2,4-D), with the effect more pronounced in C. communis. Our results demonstrate that enhancement of antioxidant enzymes and accumulation of detoxifying metabolites, coupled with the accumulation of pivotal intermediates of metabolic pathways under Al treatment collectively contribute to enhanced resistance against an array of herbicides. These findings provide insights into the invasive propensity of C. communis and T. fluminensis, particularly in acidic soil conditions prevalent in tea gardens.