GrowCNanswered grow question 3 years ago Airflow not only provides CO2 and takes away humidity and oxygen but it also strengthens the plant mechanically. It is like being out in the wind. If the plant is buffeted from a young age it develops a strong stem and branches to withstand the wind. Later in life those stronger branches can better support the weight of flowers. Also, way down near the bottom the branches can stretch more trying to reach the light, causing them to be longer and less strong.