Spawn, substrate and fruiting blocks: what is the difference?
Three familiar product names describe different parts of a mushroom-growing project.
Spawn is a starting material
Spawn contains growing mushroom mycelium on a carrier. Penn State Extension describes its role in introducing the mushroom culture to a growing substrate. Grain spawn is therefore a different purchase from a ready-to-fruit kit: check which substrate and preparation steps your project requires.
Substrate is the growing medium
Substrate provides the material in which the mushroom culture grows. Different species and methods use different materials. A listing for plain growing material, a prepared substrate and an already colonised block should not be treated as interchangeable products.
A fruiting block is further along
A prepared, colonised block has already completed some of the work that would otherwise be part of a grower's project. Check whether the selected product is described as ready to fruit, what care it needs on arrival and whether any accessories are included. Follow that product's instructions rather than a timetable for a different species.
Read the specification before buying
Compare the species, stated net contents, preparation stage and intended use. Shipping weight can include packaging and is not the same as net contents. Keep the original product instructions, and ask us about any unclear format before ordering.