Cultivating mushrooms, from the initial introduction of fungal spores to the final harvest, is a complex process requiring patience and precise environmental control. The entire cycle, which depends heavily on species and growing conditions, typically spans several weeks to a few months. Understanding the timeline involves breaking down cultivation into distinct developmental phases. The speed of growth ultimately rests on providing the fungus with an optimal habitat.
Stage 1 Inoculation and Colonization
The first phase begins with inoculation, introducing the fungal culture (spores or liquid mycelium) into a prepared substrate, such as rye grain or millet. Spores must first germinate, which can take three to 14 days before visible growth occurs. After germination, the initial growth phase is the formation of mycelium, a network of fine, white threads called hyphae.
Following germination, the mycelium begins colonization, rapidly spreading throughout and digesting the nutrient-rich substrate. Full colonization typically requires a steady temperature between 75–81°F (24–27°C) and takes approximately two to four weeks. Fast-growing species may finish in as little as 10 to 14 days. A fully colonized substrate, often called a mycelial cake, appears completely white and dense, indicating it has stored enough energy to begin producing mushrooms.
Stage 2 Pinning and Fruiting
The second stage involves transitioning the fully colonized substrate to the reproductive phase, known as fruiting. This transition is initiated by environmental changes, including a drop in temperature, increased fresh air exchange, and higher humidity. The appearance of tiny, immature mushrooms, called primordia or “pins,” marks the start of this stage.
Pinning usually occurs within five to 10 days after the fruiting conditions have been introduced. These pins quickly develop into mature fruiting bodies, which is the fastest period in the entire cycle. Mushrooms can often double in size daily and reach harvestable maturity three to seven days after the pins first appear. Maintaining high humidity, often between 85% and 95%, is necessary during this rapid growth to ensure proper development.
Stage 3 Harvesting and Subsequent Flushes
The optimal time to harvest is typically just before or immediately after the veil, the membrane connecting the cap to the stem, begins to break. Harvesting at this point maximizes the mushroom’s size and potency. It also prevents the release of spores that can inhibit future growth. The initial collection of mature mushrooms is known as the “first flush,” and it represents the most abundant yield.
After the first harvest, the mycelial cake is allowed a brief recovery period before producing subsequent rounds of mushrooms, known as “flushes.” These additional flushes usually appear every five to 12 days after the previous harvest. While later flushes may yield fewer individual mushrooms, the ones that grow are sometimes larger, and the substrate can continue to produce for several weeks.
Variables That Affect Growth Speed
The timelines provided for each stage are flexible because the growth rate is highly sensitive to several external and internal factors. Temperature control is a significant factor, as mycelium thrives within a specific range, generally 75–81°F (24–27°C). Temperatures outside this range will slow colonization considerably. Excessively high temperatures, particularly above 82°F (28°C), increase the risk of contamination from competing bacteria and molds, which can halt mycelial growth entirely.
The quality and type of substrate also influence the speed of colonization and growth. Substrates with high nutrient availability, such as enriched grains, allow the mycelium to spread more rapidly than less dense materials like wood chips. Furthermore, the genetic strain of the fungus plays a role, as some strains are naturally more vigorous and fast-growing than others, while older, less robust cultures may colonize slower. Proper air exchange is also important; while colonization requires limited air flow, the fruiting stage demands fresh air to prevent the buildup of carbon dioxide, which can slow growth and cause malformed mushrooms.