We study the trade effects of the 2021 supply chain disruptions on containerized agricultural exports from California ports. Our event studies show that port congestion and container shortages reduced agricultural exports by 22% from May to November 2021. The export losses exceed $3.2 billion and vary substantially across commodity groups, with California tree nut producers facing the brunt of the financial repercussions. California agriculture's losses surpass those from the 2018 China–US trade war by far. The export disruptions mirror the fact that California ports are among the least efficient globally.