This paper examines the understudied relationship between nature conservation and climate control in botanic gardens. Drawing on research conducted at Kew Gardens in West London, we analyse how the relations between climate control, techniques that allow the creation of particular microclimatic conditions in volumetric enclosures, and ex‐situ—out of nature—botanical management have changed over time. The paper shows how climate‐controlled conservation works through three spatial‐technological modes—acclimatisation, climate simulation, and climate security—that reconfigure in‐situ and ex‐situ relations. These modes increasingly transcend local environmental conditions, creating the possibility of conservation without natural climate. The paper extends existing geographies of climate control by focusing on the role of technology in permitting plant life to be moved between different geographical contexts, in enabling ex‐situ and in‐situ natures to become increasingly entwined, and in constructing enclosed conditions decoupled from local climate. Secure climate‐controlled conservation now strategically transforms ex‐situ botanic gardens into the actual sites, and in some cases the last remaining sites, of these natures.