"...We will not plant trees only but will also ensure protection," he said.
Kumar said since Bihar is spread over an area of 94,000 km with the population of more than 10.38 crore, in the given situation plantation and protection of trees can ensure protection to environment and help avert natural calamity.
Chief Minister laid the foundation stone of Rs 14.97 lakh sanctuary building on the Rajdhani Vatika ground and said this building would be known as 'Green Bhavan'.
Kumar said Bihar was left with 9 per cent forest and green areas after a separate Jharkhand state was carved out in 2000 "and we have the target to increase the forest cover and green areas to more than 15 per cent in next five years."
"We will be planting more than 24 crore trees and the forest officials should take it up as a challenge," he said.
Even trees will be planted alongside the roads, canals and other places and 'Bagwani mission' would be added in the exercise, Chief Minister said.
Deputy Chief Minister S K Modi, who also holds the additional portfolio of Forest and Environment department, was present.