Growing Mushrooms on Your Substrate and Container: Step-by-Step Guide
Growing mushrooms in containers is an easy and rewarding way to control the environment and grow fresh mushrooms at home. Whether you’re a seasoned gardener or a beginner looking to try something new. This guide will walk you through the entire process—from choosing the right substrate and container to maintaining optimal conditions for your mushrooms to thrive. With a few simple steps, you’ll be on your way to harvesting your own delicious mushrooms in no time.
Choosing Your Substrate
Your substrate is the dry organic material that your mushrooms will use as a food source. There are hundreds of different substrates you can use, and we have a comprehensive list on our website. In this guide, I’ll focus on two locally available and easy-to-find substrates: wheat straw and sawdust.
Straw Options: If you have access to wheat straw, barley straw, or rice straw, we recommend using those, especially if you’re a beginner. Straw is more forgiving, colonizes faster, and produces mushrooms more quickly than denser materials like sawdust or coffee grounds.
Choosing a Container
After selecting your substrate, it’s time to choose a container. You have endless options, but here are some guidelines:
- Porous Materials (e.g., wheat straw): If you’re using a porous and well-aerated material like wheat straw, you can choose a large container, such as a five-gallon bucket. If the container is deeper than eight inches, be sure to add holes for air exchange.
- Dense Materials (e.g., sawdust): For denser materials like sawdust or coffee grounds, use multiple smaller containers, with a minimum capacity of one gallon each. A helpful tip: oyster mushrooms prefer to grow out of small openings on the sides of the container rather than from the top.
Preparing the Substrate
The next step is to heat your substrate in water. Heating serves two purposes: it eliminates most microbial competitors and allows the substrate to absorb enough water for the next few months of mushroom production.
Here are a few methods to heat your substrate:
- Pillowcase Method: Place your substrate in an old pillowcase, submerge it in a large pot, and cover it with one to two inches of water. Heat the water to 170°F and allow the substrate to sit submerged for at least an hour.
- Heatproof Container Method: Place the pillowcase with the substrate into a heatproof container, and carefully pour 170°F water over it until submerged.
- Smaller Pots: Alternatively, use a series of smaller pots if that’s more convenient.
After heating, let the pillowcase drain for about 15 minutes, then wring out the excess water. The substrate should feel like a damp sponge—if you squeeze it tightly, no water should drip out.
Inoculating the Substrate
Inoculation is the process of mixing the mushroom spawn into the substrate. Once the substrate is cool enough to handle, spread it out on a clean surface. Make sure to clean everything the substrate will touch, including your hands, the growing container, and the cooling table. You can even wipe surfaces with isopropyl rubbing alcohol for extra cleanliness.
Break up the mushroom spawn into fine particles and mix it with the cooled substrate. You can layer the spawn and substrate in your container, or thoroughly mix them before placing them into the container.
Incubation and Fruiting
During the next three to eight weeks, the mycelium will colonize the substrate. To maintain adequate moisture during this incubation period, place the container in a large trash bag, leaving the top loosely open to allow air exchange. Keep the container in a dark location with a consistent temperature between 65°F and 85°F.
After two and a half weeks, start inspecting the container daily for the formation of small mushrooms (primordia). When you see them, move the container to a location with optimal fruiting conditions:
- Light: Oyster mushrooms need light to grow, but avoid direct sunlight.
- Temperature: A consistent range between 60°F and 80°F is ideal.
- Humidity: Maintain a high level of humidity (75% to 95%) by creating a humidity dome using a clear trash bag. Mist the interior surface of the bag one to three times daily.
- Airflow: Cut 10 to 12 half-inch holes around the trash bag to allow air exchange.
Harvesting Your Mushrooms
Three to five days after the primordia form, your mushrooms should be ready to harvest. Oyster mushrooms grow in clusters, and you’ll know they’re ready when the largest mushroom in the cluster flattens out. Harvest the entire cluster at this point.