Mushroom Reproduction: The Magic Of Button Spores

Button mushrooms are a fascinating species to cultivate at home, offering a rewarding hobby that can be practiced year-round. They are part of the Agaricus genus and are commercially bred for various properties, including hardiness. While they can be grown outdoors, it is a complicated process, and most growers opt for indoor cultivation, which requires minimal space and can yield multiple harvests. The process begins with spores, which develop into thread-like mycelium, forming a network that eventually produces mature fruiting bodies. This life cycle can be replicated at home with the help of growing kits, which provide pre-inoculated substrates, or from scratch using spores or cultures.

Using a growing kit

To begin, purchase a growing kit, which usually includes trays or boxes. Mr Fothergills White Button Mushroom Kits, for example, are organically grown and contain everything you need. You can find these kits at select stores nationwide, usually during specific seasons.

Once you have your kit, follow the instructions provided. Here is a general guide on what to expect:

• Keep the kit out of direct sunlight. Button mushrooms thrive in cool, dark places, so choose a location like a wardrobe, basement, garage, laundry room, or closet.
• Open the kit and inspect the compost. If it looks brown, close the kit and wait for about a week until it turns frosty white.
• Open the kit again and spread the casing (usually provided in the kit) over the compost, leaving it loose and fluffy.
• Mist the kit with water every 2-3 days. Keep the top damp, similar to a wet sponge, but be careful not to overwater.
• After about 2-3 weeks, you should start seeing mushrooms. Harvest them by twisting them out of the soil when ready.
• Fill in the empty spaces with more casing or peat moss to make way for new mushrooms.
• Your kit should continue to produce mushrooms for 3 to 6 months.

Remember, successful button mushroom cultivation requires methodical environmental control and attention to substrate preparation. Keep the temperature between 20°C to 25°C, and ensure the growing medium remains moist and shielded from light. With care and patience, you'll soon be able to enjoy your very own homegrown button mushrooms!

Preparing the substrate

Choose the Right Substrate Material

The type of substrate you use will depend on the specific mushroom variety you plan to grow. For button mushrooms, a mixture of organic materials such as yard waste, corn cobs, straw, and compost can be used. You can also use nitrogen-rich manure, such as horse manure, as button mushrooms thrive in this environment.

Sterilize the Substrate

Before introducing any spores or spawn, it is crucial to sterilize the substrate to prevent contamination. This can be done by pasteurization or using a pressure cooker, depending on the specific method you are following. Sterilization kills any unwanted microorganisms that could hinder mushroom growth or introduce contaminants.

Inoculate the Substrate

Once your substrate is sterile, it's time to introduce the mushroom spores or spawn. If using spores, you can order them online or collect them from wild mushrooms. Transfer the spores to a sterile agar medium, and then carefully transfer the culture to your substrate. If using a spawn, you can order pre-inoculated rye berries or use mushroom spawn from grocery store mushrooms. Mix your spawn or fully colonized rye berries into the substrate, ensuring even distribution.

Prepare a Fruiting Chamber

After inoculation, you'll need to create a controlled environment for your mushrooms to grow. This can be a simple wooden box, a tray, a monotub, or a more complex DIY fruiting chamber. The chamber should be large enough to accommodate your substrate and provide adequate space for mushroom growth. Keep your fruiting chamber in a dark, damp, and warm location, maintaining a temperature of around 70°F (21°C).

Monitor and Maintain Conditions

During the colonization phase, it's crucial to monitor and maintain the right environmental conditions. Keep the substrate moist and ensure proper airflow and humidity levels. Avoid direct sunlight and maintain the temperature within the optimal range. This phase can take several weeks, and you'll know your substrate is ready when you see a fine white webbing called mycelium forming on the surface.

Creating the right environment

Space and Setup

Button mushrooms can be grown indoors with minimal space requirements, making them ideal for apartments or small spaces. Basements, closets, or dedicated growing tents are suitable options for their cultivation. If you're growing them outdoors, a garden with finished compost or aged animal manure can be a good environment. When it comes to the setup, you can opt for a pre-made mushroom growing kit or create your own fruiting chamber. The kit provides a straightforward option with pre-inoculated substrates, while creating your own chamber offers more customisation.

Temperature and Lighting

Maintain a temperature of around 70°F (21°C) during the initial stages of growth. Once you notice the mycelium, which is the fine white webbing that signifies the start of your mushroom colony, gradually reduce the temperature to 55°F (12°C). Proper temperature management is crucial to the success of your mushroom colony. Regarding lighting, button mushrooms do not require sunlight, making them convenient for indoor gardening. However, when stimulating fruiting body formation, introduce indirect lighting of 200-500 lux on a 12-hour cycle.

Humidity and Moisture

Humidity plays a vital role in creating the right environment for button mushrooms. Mist the casing layer, which is the layer of damp potting soil or peat, to maintain 90% surface humidity. Ensure that water droplets evaporate within 3-4 hours of misting. Keep the growing area moist at all times, and consider covering it with plastic wrap or wet newspaper layers to retain moisture.

Substrate and Spores

The substrate, or growing medium, is essential for mushroom growth. You can use pre-inoculated rye berries or create your own by transferring spores to agar and then to sterilised rye berries. Another option is to use organic material, such as nitrogen-rich manure like horse manure, and inoculate it with mushroom spores. This provides the microscopic spores with the nourishment they need to develop into mushrooms.

Contamination Prevention

Contamination is a common issue when growing button mushrooms. To minimise risks, implement proper sanitation practices and use filtered air when possible. Avoid direct spraying of developing primordia, and ensure proper humidity management to prevent water droplet accumulation.

The growth cycle

First, spores, which are tiny and microscopic, will grow into mushrooms. These spores can be collected from the wild or purchased online. They can also be obtained from grocery store mushrooms. To begin the growth process, transfer the spores to agar, then make additional transfers to prevent contamination.

Next, prepare the growing environment. This can be done by filling a wooden box with nitrogen-rich manure, such as horse manure, to a depth of at least 6 inches (15 cm). Alternatively, for outdoor cultivation, spores can be added directly to finished compost or aged animal manure in the garden.

After preparing the growing medium, spread the inoculated material on top and mist it thoroughly. Keep the environment dark, damp, and warm at around 70 °F (21 °C).

After a few weeks, a fine white webbing called mycelium will appear on the surface. This is the beginning of the mushroom colony. Cover the mycelium with a couple of inches (5 cm) of damp potting soil or peat, known as the casing layer. This layer is crucial as it creates the ideal microenvironment for fruiting.

Gradually lower the temperature to 55 °F (12 °C) and maintain high humidity by misting the casing layer. Proper humidity ensures that water droplets evaporate within 3-4 hours. Introduce indirect lighting on a 12-hour cycle to stimulate fruiting body formation.

Primordia, small white or cream-colored dots, will appear 7-10 days after applying the casing. These will develop into mature mushrooms. Harvesting can be done by twisting the mushrooms out of the soil, and new mushrooms will continue to grow for 3-6 months.

Harvesting and maintenance

Harvesting button mushrooms is a simple process. When the mushrooms are ready, simply twist them out of the soil. You can then fill in the empty space with more casing to make way for new mushrooms. Your bed should continue to produce mushrooms for 3 to 6 months.

To begin growing button mushrooms, you can start with a pre-made kit, which comes with a colonized substrate ready for fruiting. Alternatively, you can start from scratch with spores or a culture, which can be purchased online or collected from the wild. Transfer the spores to agar, then make several more transfers to prevent contamination. Next, transfer the culture to sterilized rye berries, and wait for them to become fully colonized. Finally, mix the colonized rye berries with your substrate and place them in a fruiting chamber to grow.

To create an indoor bed for your mushrooms, fill a wooden box that’s at least 6 inches (15 cm) deep with nitrogen-rich manure, such as horse manure. Leave a few inches (8-9 cm) of space below the rim of the box. Spread the inoculated material from your kit on top of the soil and mist it thoroughly. Keep your bed in the dark, damp, and warm—around 70 °F.

After a few weeks, you should notice a fine white webbing on the surface of the bed, called mycelium. Cover your mycelium with a couple of inches (5 cm) of damp potting soil or peat, known as the casing layer. This layer is crucial as it creates the ideal microenvironment for fruiting. Lower the bed's temperature to 55 °F (12 °C) and maintain moisture by covering the bed with plastic wrap or wet newspaper.

Transitioning to fruiting conditions requires a gradual temperature reduction to 16-18 °C, implementing a 2 °C daily decrease to avoid shocking the mycelium. Increase fresh air exchange to 4-8 room volumes per hour while keeping CO₂ levels below 1,000 ppm. Mist the casing layer to maintain 90% surface humidity, ensuring that water droplets evaporate within 3-4 hours. Introduce indirect lighting (200-500 lux) on a 12-hour cycle to stimulate proper fruiting body formation. Primordia typically appear 7-10 days after casing application as small white or cream-colored dots on the surface.

Frequently asked questions