Mushroom Cultivation

Spores / Mycelium

In the early stage of a mushroom's growth, a spore will germinate on a food source. During germination, a thread-like filament called hypha will sprout from the spore through a germ pore. The single hypha will begin branching off into multiple hyphae, consuming nutrients, and seeking additional food sources. Eventually, the hyphae form a network-like mass called mycelium. The mycelium is the vegetive body or thallus of the fungi. You can grow mycelium by injecting spores on grain spawn or adding them to a nutrient culture called agar. Growing mycelium on agar is a preferred method used by many cultivators. The agar plate allows for the rapid growth, and if the spores were compromised, contamination is easily noticeable in the petri dish.

Acquire spores prints and spores syringes through vendors. However, ensure they are reputable before purchasing.

Grain Spawn

Young mycelium is weak and susceptible to contamination. Contamination could be other fungal species or bacteria. Your goal is to protect the mycelium in a sterile environment until it is healthy enough to fend off any intruders. Sterilized jars or bags of grain spawn can isolate the mycelium from contaminates. There are many types of grain, and some have advantages over others.

Types of Grain Spawn

• Wild Bird Seed
• Rye Berries
• Millet
• Pop Corn
• Oats
• Barley
• And More

The time it takes to colonize the grain spawn depends on the species and conditions. Generally, the mycelium will fully colonize the grain spawn in about 1-4 weeks. Room temperature is usually ideal, but again it depends on the species. Fully colonized grain spawn is white, and hardly any grain is visible (see photo).

How to Prepare Grain Spawn

Bulk Substrate

In the next stage, the mycelium needs to expand in volume. The fully colonizes grain spawn is used to inoculate a bulk substrate. A bulk substrate is an abundant source of nutrients. In nature, this could be inside a tree, a log, stump, leave litter, or other organic debris on the forest floor. In a controlled environment, the chosen substrate depends on the species of mushroom you are growing.

Pasteurizing the substrate is highly recommended to kill off any microbes. The sterile substrate and grain spawn are stored in a monotub or grow bag. These vessels are ideal as you can control humidity, airflow, temperature, light, and other factors to aid in your mushrooms' growth. An optional non-organic casing could be added to the top of the substrate as an extra layer of protection. As the mycelium colonizes the substrate, it produces heat and carbon dioxide (CO₂). The time it takes for the substrate to colonize, relies on the volume of the substrate, the quantity of spawn used, and overall conditions.

Fruiting

As the bulk substrate is nearing full colonization, you can place your mushrooms into fruiting conditions. Typically fruiting conditions consist of lowering the temperature, regulating the FAE (fresh air exchange), maintaining high humidity, and introducing a light cycle (12 hour on / 12 hour off). Light is often confusing when it comes to mushroom cultivation. Fungi use light near the 5500k spectrum as a signal to grow, not as an energy source like plants (photosynthesis). When done correctly, the mycelium begins forming hyphal knots that evolved into primordia or pins. In the proceeding days, the pins will rapidly grow into fully developed mushrooms. Once mature, you can finally harvest your hard work. After harvesting the first flush of mushrooms, you can prepare your substrate for subsequent flushes.