As much as possible, take your students outside. Getting it touch with nature makes people more apt to want to protect it. Even if you’re not specifically teaching an environmental concept at the time, just being outside in the sunshine is important. You can sit in the grass and read a book or work on math equations. It might be difficult at first to keep everyone focused on the task at hand, but the more often you do it, the more the children will become accustomed to it and appreciate their time outdoors.
Another way to get a quick glimpse of natural world is to take an outdoor route when you’re going from one area of the school to another. It might be a longer walk to find the nearest exit to your classroom and then traipse around the building until you find the nearest entrance to the cafeteria, gym, or library but the time outside is a tiny opportunity to enrich your class. Did anyone see a bird or some other type animal? Did anyone see a bug? What types of plants are growing? What was the weather like? The first couple of times, you can devote a little class time to discuss what the students experienced. Make a large bulletin board showing your school and grounds. The students can regularly draw pictures of what they saw and add them to the board. Each time you take a quick walk, pick one or two students to add a drawing during their space time.