Each school — 30,000 in total — will be sent about 400 Scots pine, alder and silver birch seeds from the Forestry Commission's tree nurseries.
The education project, Seeds for Schools, highlights trees' role in protecting the world from the effects of climate change.
The initiative, announced in February, will send DVDs with the packets of native tree seeds to all the nation's primary and secondary schools in the next few weeks.
Seeds for Schools is spearheaded by the News of the World newspaper and the Forestry Commission, and supported by ministers and celebrities.
Trees can be planted in school grounds or public green spaces, parks, churchyards or sites made available by other owners.
Children from six year olds to early secondary-school age were the main target, said News of the World deputy managing editor Paul Nicholas.
Forestry Commission director-general Tim Rollinson said: "Climate change will have catastrophic consequences for the Earth if we don't take decisive action. Among the most important things we must do to prevent climate change disaster are to conserve trees and forests, restore lost forests and manage and use them sustainably."