The impressive sculpture is one of an array of projects, events and initiatives across the country to mark the monarch's milestone seven decades on the throne.
What is the 'Jubilee Tree of Trees'?
The Jubilee Tree of Trees is a huge 70ft tree sculpture made from 350 individual saplings from native British tree species.
The sculpture, which will stand as tall as three giraffes, has been designed by renowned British architect Thomas Heatherwick, whose past designs include London’s Coal Drops Yard and the 16-tonne Olympic Cauldron that opened the London 2012 Games.
Read more: When is the Queen's Platinum Jubilee?
The main body of the sculpture is being crafted from reclaimed and new steel, sourced from local suppliers across the country.
It will have timber branches sprouting from its upper boughs, each one containing aluminium pots embossed with the Queen's cypher containing the saplings, therefore creating a 'tree of trees'.
It will be partly made from old surplus steel and materials sourced from UK suppliers to minimise transportation, energy use and waste.
The Tree of Trees reflects the planting of more than one million trees as part of the Queen’s Green Canopy, a tree-planting initiative created to mark the Queen's Jubilee which invites people from across the United Kingdom to "Plant a Tree for the Jubilee".
Heatherwick said: "The structure is coming together from workshops and nurseries across the country as one part of an incredible community campaign that’s literally changing the landscape of our nation."
Royal tree-planting is often used to commemorate official visits — during her reign the Queen has planted more than 1,500 trees across the world.
When will it open?
The Tree of Trees will also serve as the principal beacon lighting at Buckingham Palace during the Platinum Jubilee celebrations.
It will be lit during a special ceremony on the evening of Thursday, 2 June, an event that is expected to be attended by some members of the Royal Family.
A Palace spokeswoman said: "This will take the form of a lighting installation with the Queen’s Green Canopy Tree of Trees sculpture and projections onto the front of Buckingham Palace.
"This innovative new way of taking part in the beacon lighting will reflect the Royal Family’s long history of championing environmental causes.”
She added: "It’s 21 metres high – that’s the height of three giraffes."
How can you see it?
The Tree of Trees will be erected outside Buckingham Palace as part of the Queen's Platinum Jubilee celebrations, and will be visible throughout the Bank Holiday weekend in June.
Once the structure is taken down, the saplings that form it will be donated to community groups, charities and organisations in recognition of their services, ready to be used when the next tree-planting season starts in October.
What is the Queen's Green Canopy initiative?
The Queen announced the launch of her Green Canopy initiative in May last year, calling on members of the public across the UK to plant a tree when planting season began in autumn.
Last month, she said she was "deeply touched" by the public’s efforts as it was revealed that more than one million trees had been planted in her name.
In a written message, she said: "As the planting season draws to a close, I send my sincere thanks to everyone across the country who has planted a tree to celebrate my Platinum Jubilee,” the Queen said in a written message.
"I am deeply touched that so many community groups, schools, families and individuals have made their own unique contributions to the Green Canopy initiative.
"I hope your jubilee trees flourish and grow for many years to come, for future generations to enjoy."
As well as inviting the planting of new trees, The Queen’s Green Canopy will dedicate a network of 70 ancient woodlands across the UK and identify 70 ancient trees to celebrate the jubilee.