Mr Speaker has planted a Red Windsor tree in Speaker’s Green as part of the Woodland Trust’s Jubilee Woods Project.
The tree is one of six million that will be planted across the UK as part of the project, which is a celebration of the Queen’s Diamond Jubilee.
Speaker Bercow said he was “delighted” to show his support for the project.
More than three million trees have already been planted, with the rest expected to be in place by the end of the year.
The Trust has confirmed that 60 special Diamond Woods - each of at least 60 acres – will be planted across the UK.
”I am delighted to be planting this tree today to mark the Diamond Jubilee and Jubilee Woods project," Mr Speaker said.
"The Woodland Trust's Jubilee Woods project is a fine example of the enormous success of the Jubilee festivities in bringing people together to celebrate Her Majesty’s 60 years of dedication to public service.”
The Red Windsor, a frost hardy apple tree, was sourced in the Speaker’s Buckingham constituency.
MPs and peers from all parties, including Commons leader Andrew Lansley and his shadow Angela Eagle, and the clerk of the Commons Robert Rogers, were present to witness the tree planting.
Sue Holden, Woodland Trust Chief Executive said: "We are absolutely delighted that Mr Speaker has agreed to help start the autumn tree planting season by planting a Red Windsor and kick off the Trust’s challenge of planting the final 3 million trees.
"Creating new woodland is extremely important and even more so as we await the Government’s response to the recommendations of the Independent Panel on Forestry including its call to increase woodland cover in England from 10 to 15%
“Schools, communities, organisations and individuals have planted trees this year as a very special tribute to The Queen, but at the same time these trees are creating something living and lasting to hand on to future generations. It’s a great way to celebrate the Jubilee but also it’s a chance to make your mark on Britain’s future.”