This research reports a novel polylactic acid (PLA) blend with high density polyethylene (HDPE) and polyethylene graft maleic anhydride (PE‐g‐MAH) to mitigate the PLA degradation issues associated with high temperatures, soil and water exposure. The blend was prepared with a melt blending process and directly printed with a custom‐built pellet printer to maintain the “as prepared” properties. Thermal stability was analyzed in terms of mechanical strength at different bed temperatures and postprinting aging for 10 days. Soil burial degradation and water absorption were investigated in terms of mechanical strength and effects on mass at three intervals (15, 30, 45 days). The proposed blend revealed high stability to all three degradation mechanisms due to the chemical grafting along with physical interlocking. Finally, Fourier transform infrared spectroscopy (FTIR), differential scanning calorimetry (DSC), thermogravimetric analysis (TGA) and scanning electron microscopy (SEM) were used to confirm the enhancement in molecular interactions, melt crystallization, onset temperatures and phase distribution, respectively.