In the United States Senate, filling the tree is a procedure by which the majority leader can prevent amendments to a piece of legislation from being voted on.
[1] The Senate majority leader has a traditional right to be recognized first for the purposes of offering amendments on legislation.
Some senators will reject a bill if they feel they have not been given an adequate opportunity to offer amendments.
For example, Senator Susan Collins voted against the 2010 Defense Authorization Bill although she largely supported the substance of the bill, citing the filling of the amendment tree by Senate Majority Leader Harry Reid.
[4] Reid used this tactic during the Consolidated Appropriations Act, 2014 Senate floor debate, preventing amendments that would have removed the provisions that rolled back Section 716 (derivatives guarantees by the FDIC) of the Dodd-Frank legislation.