This study presents a new technique, the "Which plant am I?" game, which helps to increase pupils' plant knowledge, while motivate them to become familiar with more plants. On the other hand pupils' plant knowledge was tested in Serbia. The "Which Plant Am I?" game was tested with two groups of pupils (in average 11 years old). Pupils in the experimental group took part in outdoor classes and played the "Which plant am I?" game. Pupils of the control group observed plants only in the classroom. This technique can deliver significant improvement in pupils' knowledge about plants and motivate them through an active and playful learning process. This technique can be one possible solution of plant blindness.