The decrease in urban green spaces limits the opportunities for adults and children to experience nature and learn about the environment. Yet, it is only when children experience nature in the outdoors that they can learn best to love it and strive to preserve it. As such, the need to include biodiversity studies in the curriculum becomes a pressing demand on today's teachers. In this article, the authors describe how they established a long-term plant biodiversity study of a forested urban green space and suggest how other teachers and students could implement this study. In their study, the authors worked with middle school and high school students, both within a classroom setting and as a part of extracurricular activities. The authors found that the effectiveness was uniform across the entire spectrum of age groups and settings; the level of motivation and enthusiasm among students was very high in all groups. In this article, the author provides details of how they set up plots and initially collected data for their long-term plant biodiversity study, as well as suggestions for how such data may be analyzed. The authors also show how their project tied in with the "National Standards for Science Education" and its interdisciplinary connections. In the second part of the article, the authors highlight changes to conduct the study even with limited resources. Their guidelines can be used to set up plots in any forested green space in any school's vicinity. (Contains 5 figures and 3 tables.)