California Sees Worst Mushroom Poisoning Spike in Decades, Officials Say

Health officials in Northern California are urging residents to stop eating foraged mushrooms after a Sonoma County resident died last weekend from ingesting toxic fungi.

According to county officials, California is experiencing its largest spike in mushroom poisonings in at least 30 years. Since November, there have been 35 confirmed cases statewide, resulting in at least three deaths and three liver transplants. Many of the recent incidents are linked to a widespread “super bloom” of death cap mushrooms, fueled by mild temperatures and early-season rains.

Death caps—scientifically known as Amanita phalloides—are among the most dangerous mushrooms in the world. They are responsible for more than 90% of mushroom-related deaths and have a mortality rate of around 50%. The mushrooms can appear white, yellow, green, or bronze and are often mistaken for edible varieties commonly found in Northern California.

The Sonoma County Department of Health Services warns that even experienced foragers can misidentify toxic mushrooms. Symptoms typically begin six to 24 hours after ingestion and may resemble the flu, including vomiting, nausea, stomach pain, and diarrhea. In some cases, symptoms temporarily improve before severe liver damage develops days later.

Officials also caution that cooking, boiling, or freezing toxic mushrooms does not make them safe. Residents are advised to keep children and pets away from wild fungi and to purchase mushrooms only from trusted retailers.