Chinese companies have shipped shiitake and other fully colonized substrate blocks to the US at prices that appear commercially unviable. In 2024, 3,583 shipping containers from China arrived in the US, producing 87 million pounds of shiitake valued at nearly $400 million. Labeled as "spawn," these imports incurred a 1.4% import duty and, being harvested/packaged in the US, were sold as "Product of the USA." Domestic producers are concerned that these Chinese producers may be engaging in unfair or illegal trade practices.
Under 19 CFR Part 175, CBP must audit pricing mechanisms of exporting and importing companies if a domestic interested party requests it. If the importer and exporter are related, CBP must use pricing methods other than transactional ones, incorporating data from domestic producers.
We invite US mushroom farmers who produce or purchase spawn and/or substrate blocks to complete this survey. Your responses will support our petition to CBP. The survey takes approximately 10 minutes, and all questions are voluntary—skip any you prefer not to answer. Producers of all sizes are encouraged to participate.
