The party's manifesto, which has been launched today, states that there will be free universal early education and childcare for all children, with children starting formal education at age seven. Current rules are that children must start school the September after their fourth birthday.
The pledge to guarantee free universal early education and childcare for all children is the most ambitious to be set out by a political party ahead of next month's general election.
Currently all three- and four-year-olds are eligible for 15 hours of government funded care a week, but this will be extended to 30 hours from September.
The Liberal Democrats' plans have said that their long-term goal is to provide 30 hours a week of free care to all children aged from two to four. Initially, however, it will offer 15 hours of free care weekly to all two-year-olds, and 15 hours weekly to working parents of children aged from nine months to two years.
Labour also plans to extend the current government's offer by delivering 30 hours of government-funded care a week to all two-year-olds. Its manifesto also states it would make "some" childcare available for one-year-olds.
Pre-school Learning Alliance chief executive Neil Leitch said he is "sceptical" the Green Party's plans would work in practice.
"The Green Party's manifesto calls for free universal early years education and childcare, with formal education starting at age seven, yet contains no information explaining how many hours would be offered each week, or how this would be funded or implemented," he said.
"Given that the sector is currently struggling to cover the costs and address the logistics of delivering 30 hours to three- and four-year-old children of working parents, we are sceptical about how the Greens would be able to work with the sector to achieve their ideas in practice.
"If politicians wish to win the support of the sector, they need to present us with pragmatic policies that will see neither providers, nor parents, left out of pocket."
Purnima Tanuku, chief executive of National Day Nurseries Association said the promise of free universal childcare is "very ambitious".
"Any pledge to increase the current offer to parents needs to deal with the unfair funding first, then make sure all schemes have sufficient investment to allow all childcare providers to deliver high-quality childcare sustainably," she added.
"The party also pledges to start a child's formal schooling from age seven. It must be recognised that early years is a distinct stage in a child's development, with unique provision to reflect this ahead of their formal schooling.
"This principle is welcome, but schools and education experts should be widely consulted first on any proposal for formal education to start at the late age of seven."
The Green Party has also published a separate Youth Manifesto, which includes plans to make youth services a "priority public service" by increasing spending on youth services, youth councils, and non-curricular education and training.
The party has also pledged to introduce votes at 16, and ensure "non-biased political education" is taught in schools.
The Greens would require local authorities to stop declaring young people as "intentionally homeless", and ensure they help all those needing housing.
The party would also introduce changes to housing benefit to ensure young people are entitled to the same amount as adults.
Speaking at the launch, Green Party co-leader Jonathan Bartley accused the Conservative government of launching "a war on young people, taking public debt and hanging it around the necks of the next generation".
"Young people matter and a political party that fails to work with and listen to young people, that ignores them in favour of older voters, that thinks of the future only in terms of their tenure in office not the lifetime of today's youth, is not a political party at all but a closed-off clique," he said.
"We're offering young people a better future, whether it's a quality education, secure job, or a warm, safe home."