Spawn is mycelium, which has been grown on some sort of substrate, often grain, for the sole purpose; of inoculating more substrate. A bag of spawn is not intended to directly grow mushrooms itself, it’s a bag of inoculant. Having great spawn is a critical part of growing great mushrooms.
Spawn comes in all different types. You can have dowel spawn, grown on little wooden dowels for log cultivation, you can have sawdust spawn grown on sawdust, you can even have popcorn spawn, grown on popping corn. The most common type of spawn is called grain spawn and the most common grains used are wheat, barley or millet or a mix of those grains.
If you look closely at the photos you can see the grain, the mix of grass seeds, and the white fuzzy stuff, which is the mycelium growing through the grain.
We don't produce spawn for sale ourselves at Milkwood - instead, see below for our preferred suppliers.
Over the years from the feedback of thousands of students from our Home Mushroom Cultivation courses, we've gotten to know the best suppliers of mushroom spawn.
Aussie Mushroom Supplies – the best Australian source of grain spawn. You can purchase any of the "Mushroom Spawn Bag 1.7kg" varieties on the linked page.
Disclosure: Milkwood has partnered with Aussie Mushroom Supplies to provide the best type of spawn for beginner growers. The link above is an affiliate link, if you use it to buy spawn, Milkwood will be paid a commission. This does not change the price you pay at all, and by buying your spawn this way you are supporting two small businesses. Thank you.
Field & Forest - a great source of grain spawn located in Wisconsin, USA.
Fungi Perfecti - Pauls Stamets’ company offers a range of grain and plug spawn products located in Washington State, USA.
Currently only selling "Master" spawn which is too expensive for regular use - August 2021.
SouthWest Mushrooms - Urban mushroom farm and good source of grain spawn, located in Arizona, USA.
North Spore - source of grain spawn located in Maine, USA.
Fungi Ally - source of grain spawn located in Massachusetts, USA.
Mushroom Mountain - supplier of plug/dowel spawn and sawdust spawn (no grain spawn), USA
Circular Harvest - offer grain spawn for different varieties located in Fraser Valley BC
Hazel Grove Farm - offer kits made on sawdust that can be used as spawn for logs and gardens based in Deep Brook, Nova Scotia.
Happy Caps - offer shiitake plug spawn based in Winnipeg, Manitoba
MushRush - source of grain spawn located in KwaZulu-Natal, South Africa.
Funguys Gourmet - source of grain spawn located in Western Cape, South Africa.
Note: Pleurotus ostreatus species are not available for purchase in New Zealand.
We suggest you use Pleurotus pulmonarius (Phoenix Oyster) instead.
SporeShift Mushrooms - source of grain spawn located in North Canterbury, New Zealand.
Merit Mushrooms - supply a wide range of grain spawn from Hertfordshire in England.
Urban Farm-It - source of grain and plug spawn in Kent, England.
Gourmet Woodland Mushrooms - supply sawdust spawn from West Yorkshire, England.
Tyroler Glückspilze - spawn supplier based in Austria.
Shii-Take - grain spawn supplier based in Germany.
Mycelia - large European supplier based in Belgium.
Please let us know if you find another reliable supplier who has been in business for some time that you would recommend or if you have any trouble with any supplier on this list. We take your suggestions seriously and we will review our recommendations.