Nearly 1,500 new street trees have arrived in London as part of the mayor's manifesto pledge to make the city greener and more attractive.
During the mayoral campaign, Boris Johnson pledged to plant 10,000 new street trees in London, funding the £1m measure through efficiency savings.
He said Londoners would benefit from more wildlife, improved local air quality and reduced flood risk.
The first batch of trees will be planted across 10 London boroughs.
About 1.75m Londoners live in areas that are further than 1km from an area of space of containing nature and/or wildlife, the mayor said.
"I have made it a top priority that we make our city a more attractive place to work, live and visit and reversing the decline of street trees is one way for us to do this," he said.
"I cannot think of a more uplifting way to usher in the spring than the arrival of these brand spanking new trees."
He added: "This is just the first phase of my programme to make our communities leafier by, during my term of office, planting over 10,000 street trees in areas that have the least."
The mayor wants to see new street trees in every borough across London and additional areas are expected to be announced later this year.
The mayor aims to have all the new trees planted by the start of the 2012 Olympic Games.