Introduction

Mushroom farming is now one of the easiest and most profitable small-scale crops to grow, whether at home or commercially. One of the most popular methods is by using mushroom blocks — also known as sawdust substrate blocks. This method is space-saving, cost-effective and can yield good harvests even for beginners.

In this article, I’ll share a complete step-by-step guide on how to grow mushrooms using mushroom blocks — from preparing the materials to caring for them and harvesting your fresh mushrooms!

What is a Mushroom Block?

A mushroom block is a growing medium made from a mix of sawdust, rice bran, lime, water, and mushroom spawn (seed). This mix is packed into heat-resistant plastic bags, sterilised, and then inoculated with mushroom spawn.

Types of Mushrooms Suitable for Blocks

Some common mushrooms that grow well with this method:

  • Grey oyster mushrooms

  • White oyster mushrooms

  • Lingzhi mushrooms (commercial)

  • Shiitake mushrooms (needs cooler temperatures)

Materials Needed

✅ Sawdust (clean, dry)
✅ Rice bran
✅ Agricultural lime
✅ Clean water
✅ Mushroom spawn
✅ PP (polypropylene) heat-resistant plastic bags
✅ Neck rings & cotton plugs
✅ Steaming drum or steriliser

Steps to Make Mushroom Blocks

1️⃣ Prepare the Substrate

  • Mix sawdust, rice bran and lime in this ratio:
    80% sawdust
    15% rice bran
    5% lime

  • Add clean water until the mixture is moist. When squeezed, it should clump together but not drip water.

2️⃣ Pack the Substrate

  • Fill the mixture into the PP bags.

  • Press to compact them — each block weighs about 1–1.5 kg.

  • Fit the neck ring and plug with cotton.

3️⃣ Sterilise the Blocks

  • Steam or boil the blocks in a drum for 4–6 hours at about 95°C.

  • Make sure the heat is even to kill any harmful bacteria or fungi.

4️⃣ Cool & Inoculate

  • Let the blocks cool to room temperature.

  • Inject the mushroom spawn into the centre of each block.

  • Seal again with the cotton plug.

5️⃣ Incubation Period

  • Keep the blocks in a clean, dark place with a temperature around 25–30°C.

  • Leave for 30–60 days until the mycelium (white threads) fully colonise the block.

6️⃣ Fruiting Stage

  • When fully colonised, remove the cotton plug and cut the bag slightly.

  • Place the blocks on shelves in a shady, humid grow room.

  • Mist daily to maintain humidity of 80–90%.

Tips for Maintaining Mushroom Blocks

🌱 Keep the grow area clean and free of pests.
🌱 Avoid direct sunlight but ensure there’s low, indirect light.
🌱 Maintain the right temperature — not too hot or dry.
🌱 Mist the blocks daily with fine spray — don’t let water pool on the blocks.
🌱 Harvest when the mushrooms are large enough (usually 7–10 days after pinning).

Income Potential

A small-scale home mushroom setup can generate extra income. One mushroom block can produce about 500–700g of fresh mushrooms over its productive life (usually 3–4 harvests).

If sold for USD10–USD15 per kg, you can estimate your earnings depending on how many blocks you grow and sell.

Conclusion

The mushroom block method is a great way for beginners to start growing mushrooms with minimal space and budget. Besides enjoying them at home, you can also sell fresh mushrooms or even ready-to-grow blocks — many people love to grow their own mushrooms at home!

Good luck and happy harvesting!