Indonesia is trying to plant nearly 80 million trees in a single day, in an attempt to set a new world record and deflect criticism about deforestation.
Mr Yudhoyono declared the trees a gift to the world
Police, soldiers and local officials joined President Susilo Bambang Yudhoyono in the nationwide project.
The plan is part of a campaign launched at UN climate change talks last year.
A World Bank report puts Indonesia as the world's third largest greenhouse gas emitter - owing to deforestation, land clearing and forest fires.
President Yudhoyono took part in the planting of more than 1,000 native trees in Bogor, west Java.
Mr Yudhoyono declared the trees a gift to the world, and said the event showed Indonesia was serious about protecting the environment.
"We have been negligent in the past, now we have to get our act together," he was quoted as saying by state news agency Antara.
But he stressed that the country would need financial support from developed nations in order to protect its remaining forests.
The goal is to have 79 million native trees planted by the end of the day, and officials are hoping to set a world record.
But according to Greenpeace, Indonesia holds another less flattering record - the world's fastest deforestation rate.