We analyzed 22 years of satellite and modeled data to study how light and mixing shape phytoplankton blooms on the Argentine Continental Shelf. Blooms start earlier on the central shelf and coast, and later on the deeper, colder Patagonian Shelf. Bloom intensity is highest in nutrient-rich, well-lit waters. Light penetration and mixing are key drivers, but local ocean features also influence bloom patterns. These findings improve our ability to predict ocean productivity and ecosystem behavior.