Premise In arid ecosystems, shrub facilitation is a critical process driving plant community structure and assembly, often resulting in increased densities of annual plants beneath shrub canopies. Pollinator-mediated interactions can have fitness consequences for both plant interactors but are largely unexplored as an indirect consequence of direct shrub-annual facilitation. Methods We tested the capacity of the geographically widespread creosote bush (Larrea tridentata) to influence pollinator visitation to its annual understory during its phenological shift into spring flowering. We used small video cameras to record pollinator visitation and foraging behavior on potted transplants of a representative flowering annual. We concurrently evaluatedL. tridentata's positive role as a foundation plant in this system by measuring the associated plant and arthropod communities and deploying data loggers to measure understory microclimates. Results Pollinator visitation to the flowering annual desert dandelion,Malacothrix glabrata, was lower when beneath the canopy ofL. tridentata, and further declined throughout the study site asL. tridentataentered full bloom. We confirmed the role ofL. tridentataas a foundation species in this system through its concurrent, positive effects on annual plant cover (a proxy for biomass), the abundance and richness of the understory arthropod community and its ability to create stable microclimates. Conclusions Direct and indirect shrub effects on other species function simultaneously to shift net outcomes even within predominantly net positive facilitation complexes.