This work presents a lecture and lab series that focuses on teaching the concept of nanophytotoxicity to undergraduate students in a relatively simple experiment. In this experiment, students evaluated the phytotoxicity of engineered nanomaterials (ENMs) using mung beans (i.e., "Vigna radiata") and industrially relevant, commercially available ENMs, silicon dioxide (SiO[subscript 2]) and zinc oxide (ZnO) nanoparticles (NPs). In comparison to the control system using solutions of Nanopure water, the growth of mung beans in solutions of ZnO NPs with a concentration of 20 mg/L was severely stunted, showing clear evidence of a high level of nanophytotoxicity. The growth of mung beans in solutions of SiO[subscript 2] NPs with the same concentration was intermediate to, though statistically separate from, the aforementioned solutions, showing clear evidence of a lower level of nanophytotoxicity than for the ZnO NPs. The simplicity of the experiment and the clear phytotoxic results should make this experiment of interest to many types of students including science majors, nonmajors, and high school students.