Notice: Mushroom Spawn orders are currently full.
Production will resume in late 2019 or early 2020, when a full compliment of species and strains will be available as either grain based or sawdust based spawn in 1 pound jars or 5 pound bags. Simple grow kits including instructions may be available as well. The ‘Species & Strains’ list below will be updated once the available cultures have been propagated and confirmed to be available, so stay tuned for that announcement when it comes.
If you are interested in ordering some fresh, local mushroom spawn produced by a small scale mushroom grower right here in Manitoba, and don’t want to miss out on growing some of your own in 2020, please fill out and submit the form on the Contact Page. Be sure to mention that you are interested in staying informed as to when it comes time to pre-order your spawn and you will be added to the River City Mushrooms e-mail list. Those on the list will hear about the available of spawn first, as well as workshops, programs and other exciting events. Thank you for your interest in supporting grassroots mycology!
Ready to start growing your own fresh, local mushrooms in Winnipeg and beyond? We’ve got you covered. Freshly made mushroom spawn is all you need to start growing beautiful and delicious mushrooms. Not sure exactly what mushroom spawn is or how to use it? Check out these basic introductions before you continue..
Spawn is available in quart size glass mason jars that are fitted with specialized lids to maintain a breathable yet sterile environment within. Each jar contains 16 ounces (1 pound) of sterilized, certified organic Manitoba grown rye grain or hydrated hardwood sawdust and is inoculated with the desired mushroom species or strain of your choice.
Each inoculated jar (unit) of mushroom spawn costs $10 and is made to order. This requires a minimum of 3 days from the time of ordering to produce plus an additional incubation period of roughly 1-3 weeks (usually 10 to 14 days) for the mycelium to colonize the substrate within before it can be opened up and combined with more substrate to grow mushrooms.
Species & Strains
Mushroom spawn orders for 2019 are currently full. Stay tuned for when new species and strains are available for pre-order for the 2020 growing season.
What is Mushroom Spawn?
Mushroom spawn is the mycelium of a fungus that has been inoculated often into either grain or sawdust under sterile conditions to create spawn. is your best choice for inoculating large volumes of substrate quickly and harvesting beautiful, delicious mushrooms from early spring through to late autumn. Mycelium is the body of a fungus and is comprised of a vast, interconnected network of filaments (known individually as hyphae) that make up the structure of the fungal organism.
Mycelium can be easily recognized as a fine, usually white, thread-like material growing throughout decomposing logs, branches, rotting leaves, within the soil or virtually any other dark, moist and sheltered environments. It is this mycelium that produces mushrooms, which are the spore bearing reproductive structures of many fungi.
This mushroom spawn, when mixed with additional substrate material, colonizes it’s new environment and when certain environmental conditions are present (usually elevated oxygen levels, high humidity and a change in temperature), this stimulates the mycelium to produce mushrooms which can then be harvested or preserved and enjoyed. Spawn is often regarded as the standard method of inoculating large volumes of prepared substrate quickly.
The material that the mycelium of a fungus lives within is known as substrate. Substrates are organic materials such as wood, soil, manure or compost which the fungus breaks down by releasing digestive enzymes into the surrounding environment and producing metabolites. Substrate materials can vary greatly depending on the individual requirements of the species or strain being cultivated.
To put it simply, mushroom spawn are the ‘seeds’ which are ‘planted’ in a nutritious substrate that nourishes the mycelium until it consolidates and is stimulated to yields mushrooms. Fungi are fundamentally different from both plants and animals, yet there are parallels that can be drawn between gardening with plants and gardening with fungi.
A thorough understanding of the environmental requirements necessary for proper mushroom (or fruiting body) development such as light, fresh air and moisture levels in addition to learning to formulate and prepare substrates and properly handle mushroom mycelium is necessary in order to successfully grow mushrooms using grain or sawdust spawn.
Please be sure that you have done your homework before you choose to work with mushroom spawn. We cannot be held responsible for failure if the mushroom spawn was not stored properly, handled incorrectly or grown under detrimental conditions. Just like vegetable gardening, mushrooms require certain environments if they are to flourish and reward you with a harvest for you diligence and patience.
That being said, there our countless books, websites and online forums with detailed articles and videos which effectively demonstrate all of the necessary techniques and illustrate countless methods for growing mushrooms simply and successfully.
How do I Store Mushroom Spawn?
Do not open the jar of bag until you are ready to use it!
The species and varieties of mushroom spawn that I have available are generally quite adaptable and will grow strongly and remain healthy at a wide range of temperatures, although room temperature is best. Under most circumstances, if you are comfortable then the mycelium will be comfortable too.
Temperatures below 10°C can cause the mycelium to grow much slower and refrigerated temperatures often cause the mycelium to enter a state similar to hibernation and hardly grow, if at all. Freezing temperatures are lethal to most species in this form, so never put spawn in your freezer and parts of your fridge that have a tendency to freeze.
Temperatures in excess of 30°C can also be harmful, as can direct sunlight. Indirect light however is beneficial to the growing mycelium and so avoid storing them away in dark cupboards or pantries which also do not have good ventilation or fresh air (unless incubation in dark environments is required, as is true for some species). Places where the ambient temperature fluctuates throughout the day should also be avoided in order to produce consistent growth.
On top of the fridge, on a shelf, on the counter in a kitchen or on a bedside table or desk are all good places to store your mushroom spawn, as long as direct light is avoided but indirect light is available and the room has good ventilation. Also avoid storing your spawn near sources of possible mold or yeast contamination such as compost pails, trash cans, in washrooms, or on the floor.
Under ideal conditions, mycelium should be visible growing within the spawn at around 1-2 weeks after the inoculation date found on the jar label. Once the grain or sawdust inside is around 20-30% covered by mycelium, giving the jar or bag a vigorous shake or gentle massage, respectively, for around 20 seconds or so helps to break up the growing mycelium and redistribute hyphal fragments, helping the remaining substrate to colonize faster.
Once the mycelium has completely covered the grain or hardwood sawdust and has had a chance to briefly consolidate, it is ready to be used. If you are not yet ready to use your mature spawn, simply place the spawn in your fridge or a cold cellar until you are ready to incorporate it into a prepared substrate mixture of your choice.
If the mushroom spawn is fully colonized and allowed to continue growing, the mycelium may enter a state of senescence which results in a noticeable loss of vigour once mixed with substrate material. Storing the recently colonized spawn under cooler temperatures prevents it from become over-mature and therefore preserves it’s vigor.
How Do I Use My Spawn?
Mushroom spawn can be added to your prepared, hydrated substrate mixture of choice at a ratio of 1 part spawn to 3 or 4 parts substrate. This will result in the spawn making up 25-33% of the total volume. I recommend 1:3 or 1:4 ratio for beginning and novice mushroom cultivators since this will allow for faster colonization and also discourage contaminates from proliferating.
Commercial mushroom growers, working under mostly if not entirely sterile conditions, often inoculate at ratios of 1:5, 1:8 or even as low as 1:10 or even 1:20. When you are just starting out, especially if you are not pasteurizing or sterilizing your substrate (with the exception of wine cap mushrooms, Stropharia rugosoannulata), working with higher amounts of spawn to substrate encourages success.
As you continue to work with mushrooms, diversify the species and varieties that you work with and refine your techniques, you can begin to work with smaller ratios of spawn to substrate and still experience adequate colonization and yields. Oyster mushrooms (Pleurotus spp.), the choice of many beginner mushroom growers, are particularly adaptable and aggressive enough to handle less than ideal conditions and still perform well.
After you have mixed together your spawn and hydrated substrate mixture, you may then place your brand new mushroom ‘kit’ in a suitable place for the mycelium from the spawn to begin colonizing the new, nutritious substrate material and working hard to produce beautiful and delicious mushrooms for you! For more information on what these sorts of suitable places might be, pleased consult the Resources page for further reading or check out the upcoming programs below below to attend a course or workshop to see how it’s done. Thanks again for reading and happy growing!