Our planet is increasingly facing biophysical challenges that associate with phenomena like frequent droughts, water scarcity, wildfires, soil degradation, pollution. Safeguarding ecosystems is a necessity and a demanding task, particularly when dealing with issues related to biodiversity. Education is a powerful tool to help retain healthy ecosystems and alleviate those problems. By understanding their structure and function, it enables their sustainable manage. Specifically, terrestrial Mediterranean ecosystems, are characterized by high levels of biodiversity, with only one eighth of them being preserved. For urban ecosystems, the level of biodiversity is higher due to the additional planting of alien exotic species. Research has indicated that for the Greek urban areas, such as parks and school yards, there are plant species that can cause substantial health problems to humans. Laureus nobilis, is one of them that can even cause death. Another species that is fatal to humans but has extremely beautiful dark green foliage and fleshy red small fruits is Taxus baccata. Consequently, actions such as “planting the right species at the right spot” and “continuous monitoring” help maintain heathy urban environments for humans. With no doubt, education is a powerful tool that results to well trained professionals that can transfer knowledge and inform the public on those environmental issues and practices that enable detect and alleviate those problems.