This paper studies the new repositories of specimens and knowledge that emerged from Sweden's first “phytotron,” a modern climate laboratory for plant research established in Stockholm in the 1960s. Different aspects and scales of technoscientific plant and crop growth came together under one roof: inhouse trials on the timing and spacing of trees and crops, postwar domestic policies to modernize a largely rural country, and Swedish forest geneticists' expertise in international efforts to improve forest stand and productivity globally. I argue that a scalar analysis of scientific forestry can help identify and assess the historical contingencies and contexts that formed the interventions in planetary order invoked by the Anthropocene.