Find a variety of trees to measure on the school grounds or local park, and use this lesson plan as a guide.
On average, trees in the shade or in a forest grow 1.5cm per year. In full light they can grow 2.5cms. However, all trees grow at different rates and other factors will affect this rate, such as soil type, access to water and prevailing winds, closeness to the sea/salty winds, being eaten by animals, etc. [...]