This article examines the place of botanical gardens in the public sphere, historically and currently, analyzing the variety of cultural dynamics shaping these locales. Botanical gardens are complex cultural sites where multispecies relations are cultivated and managed. These sites typically combine scientific inquiry with conservation efforts and public attractions. Botanical gardens in Spain offer a distinctive perspective on these locations because of their regional orientations, histories of empire, and distinctive research programs. Located in Spain’s three largest cities—Madrid, Barcelona, and Valencia—these gardens provide an opportunity to think about multispecies relations that unfold in institutional settings located in dense urban zones. This article theorizes multispecies publics as distinctive cultural assemblages that distinctly align humans and nonhumans in relations of care. These publics combine deep historical roots with considerable current transformative potential for reimagining urban space and the nation.