Planting is planned over the next 25 years across a 120-mile stretch of northern England along the M62 corridor to boost habitat for wildlife including birds and bats, protect species such as the red squirrel and provide more access to woodlands for millions of people living in the area.
The Woodland Trust, in partnership with the Community Forest Trust and the five Community Forests, aims to plant woodland totalling 25,000 hectares (62,000 acres), in a project which is forecast to cost Â£500 million over 25 years.
It could generate an estimated Â£2 billion for the economy in growth in tourism and visits to the area, boosting rural businesses and generating jobs, increasing property values, and reducing the economic impacts of flooding, the scheme's backers say.
The Northern Forest is set to form part of the Government's long-awaited 25-year environment plan and Â£5.7 million of public money is being committed to launch the scheme.
It is hoped government funding to kick-start planting will help encourage private landowners to come on board with the project.
Planting will begin in March at the Woodland Trust's 680-hectare (1,680-acre) Northern Forest flagship site at Smithills, Bolton, supported by funding from the Heritage Lottery Fund.
The Northern Forest will connect the five Community Forests in the north; the Mersey Forest, Manchester City of Trees, South Yorkshire Community Forest, the Leeds White Rose Forest and the HEYwoods Project, with woodland created in and around major urban centres such as Chester, Liverpool, Leeds, and Manchester.
Woodlands will be a mix of native broadleaf trees such as oaks and conifers including spruce and pine, and will be targeted at areas where they can boost health and wellbeing.
Establishing a new network of forests in England including on farmland, and funding larger-scale woodland and forest creation, also forms part of the Government's clean growth strategy to meet legally binding targets to cut climate emissions.
Austin Brady, director of conservation at the Woodland Trust, said: "The Northern Forest will accelerate the creation of new woodland and support sustainable management of existing woods right across the area.
"Planting many more trees, woods and forests will deliver a better environment for all - locking up carbon on a large scale, boosting wildlife habitat and greening our towns and cities.
"The Woodland Trust and Community Forests will use new and innovative mechanisms to engage communities and a wide range of partners in delivering the forest.