"The Diamond Jubilee wood will be the largest continuous block of woodland to be owned by a single organisation," said a Woodland Trust spokeswoman.
Dense woods, open spaces and a lake will define the wood in Leicestershire, planting of which is due to start next year. The National Forest Company (NFC) owns some of the land with the rest in private ownership.
At present, former opencast land, patches of ancient woodland and arable fields form most of the site.
The new woodland would attract species of wildlife such as skylarks, drawn to the open spaces, said NFC chief executive Sophie Churchill. It would be an ideal habitat for the threatened lesser-spotted woodpecker.
Woodland Trust chief executive Sue Holden added: "We need help to create woodland for the nation, to give everyone access to the beauty of the natural world and to create a legacy for the Queen's jubilee."