Green party members will be urged to make a "judgment call" and back the Yes Scotland campaign for independence.
Patrick Harvie, the party co-convener, said that formally endorsing the movement does not mean having to surrender distinct policies on the economy and environment. Delegates at the party's conference in Glasgow will also be able to choose to form their own campaign or join forces with other organisations.
The key votes follow a decision by the Greens' ruling council to check with the wider membership before formally endorsing Yes Scotland, launched as a cross-party movement earlier this year.
Mr Harvie said: "Back in May I took part in the launch of Yes Scotland to explain why Greens are not nationalists. Even before the launch, we made it clear that Yes Scotland needed to be more than just the SNP, with little progress in the early days. But our message has been taken seriously, and Yes Scotland has developed significantly.
"Taking part in Yes Scotland would not mean surrendering our progressive policies on the economy, social justice and the environment. And we would reassert our opposition to an independent Scotland throwing billions of pounds at unnecessary military spending and the Nato nuclear alliance.
"Scottish Greens are more comfortable than most parties with the range of views we know our members and voters hold about independence. We won't pretend that it's the solution to every problem, or that it's a disaster waiting to happen. We know the truth is somewhere in between.
"Unconvinced but open-minded voters are unlikely to be persuaded by an SNP rally bedecked with saltires. This is a judgment call, not an ideology. And the Scottish Greens can bring a distinctive and transformational agenda to the debate on Scotland's future."
Greens want an "autonomous and decentralised" country with a written constitution and Bill of Rights before powers are transferred from Westminster.
Recognising differing opinions on independence within the party, the conference document accepts that some members will campaign on an individual basis for a No vote in the referendum, expected to take place in autumn 2014. Members could also officially drop support for a multi-option referendum in favour of a simple Yes-No ballot.
As well as seeking "full participation" in the Yes Scotland organisation, delegates may also back the Radical Independence Conference which is due to be held on November 24 in Glasgow. That movement calls for a republic, which is in line with Green party support for an elected head of state, and has been backed by Mr Harvie.