How to Grow Mushrooms Step by Step: A Beginner’s Guide

Growing mushrooms is one of the most rewarding and sustainable agribusiness ventures you can start with minimal capital. It’s a year-round activity that makes excellent use of agricultural waste like wheat straw and even unused structures such as old chicken houses or idle rooms.

Below is a practical guide to take you through every stage of mushroom production, from preparing compost to harvesting your first crop.

Stage 1: Preparing the Compost

Mushrooms don’t grow directly in soil; they need a special growing medium known as compost, which supplies them with nutrients. You can make your own compost using easily available materials:

Ingredients:

• Wheat or rice bran – 20 kg

• CAN (Calcium Ammonium Nitrate) – 3 kg

• Urea – 3 kg

• Gypsum – 20 kg

How to Prepare

1. Mix all the ingredients thoroughly and add enough water to make the pile moist (not soggy).

2. Pile the compost into a 1.5m x 1.5m heap.

3. Turn the compost on the 4th, 8th, and 12th days. On the 12th day, add 10 kg of gypsum.

4. On the 16th day, add another 10 kg of gypsum and turn again.

5. The final turning is done on the 20th day.

Your compost is ready when:

• The straw becomes soft and easy to bend.

• It has a dark brown color.

• It emits a strong ammonia-like smell.

• It holds water well.

Finally, pack the compost into clear plastic bags. These help you monitor the internal changes and detect any signs of contamination early. Move the bags to your mushroom house for the next stage.

Stage 2: Spawning (Planting the Mushrooms)

Spawning is the actual process of planting mushroom “seeds,” known as spawn, into the compost.

Steps:

1. Using your finger, make small holes in the compost and place small portions of spawn inside.

2. Maintain a temperature of around 25°C in the room.

3. Keep the room humid by using a humidifier or by spraying water on the walls and floor.

In a few days, you’ll start to see white, thread-like growth spreading through the compost — a sign that your spawn is colonizing successfully.

Stage 3: Casing (Soil Layering)

Once the compost surface turns white, it’s time for casing, adding a layer of soil on top to support mushroom growth.

Tips for Casing:

• Use forest soil, as it’s rich in organic matter.

• Before use, sterilize the soil to remove insects or diseases. You can treat it with a mild formalin solution for this purpose.

• Spread a thin, even layer of the soil on the compost surface.

Stage 4: Growth and Harvesting

This is the most exciting part! After casing, mushrooms start to sprout within a few weeks.

Key Tips:

• Keep the environment humid and cool throughout this period.

• Mushrooms can be harvested several times (flushes) from the same compost.

• The full process, from composting to final harvest, takes about 15 weeks.

Marketing Your Mushrooms

Mushrooms are in high demand due to their nutritional value and growing popularity among vegetarians. You can sell your produce to:

• Schools and institutions

• Hotels and restaurants

• Supermarkets and groceries

• Health food shops

For reliable spawn, you can source from Egerton University (Department of Biological Sciences) or other certified mushroom farms in Kenya.

Final Thoughts

Mushroom farming is a profitable and eco-friendly venture that transforms agricultural waste into a high-value product. With patience, consistency, and proper hygiene, you can turn even a small room into a thriving mushroom production unit.

Start small, learn the process, and scale up as your skills and market grow, one bag of compost at a time. 🍄