Materials required include seed, nearly 2 million native trees for advance planting, and up to 5m more to be bought in the next 10 years, to help blend the route into the surrounding landscape.
The total value of the contracts will be £5m - £9m, with the first contract award in September 2016. HS2 says the autumn contract signing will provide "time for trees to be grown and ready for planting throughout the construction period".
The tender has now been published on the website of the Official Journal of the European Union. The time limit for accessing documents is midday on 26 April, with PQQs and registrations of interest due 3 May.
The scope of the contract is to establish a supply agreement by which HS2 Ltd can instruct the collecting of seed, the growing and supply of plant material to meet tree planting requirements for Phase One. The term would extend over a maximum 10-year period.
In the early stages HS2 envisions 1,800,000 trees being grown to contract from locally-sourced seed for advanced planting areas.
A further 5,200,000 may be required subject to requirements over the life of the project, as well as some additional trees to replace failed or damaged plants, although these are not guaranteed.
HS2 Ltd has also announced a shortlist of companies in the race to win packages of work along the line. Nine bidders have been shortlisted for between £7.1 and £11.8bn worth of civil engineering work between London and Crewe.
Civil engineering contracts covering the 140 miles from London to Birmingham are expected to be signed in 2017 with the start of work on site one year later.
The HS2 Bill is due to return to the Commons today, 23 March, for the latest vote in the legislative process, before the bill moves on to the Lords. Royal Assent is expected at the end of the year, with the start of construction in 2017.
HS2 Ltd also published details of engineering design work worth up to £500 million for developing the detailed plans for Phase Two, including Crewe to Manchester and Birmingham to Leeds, ahead of a formal route decision on Phase Two, expected in the autumn.