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Reishi Mushroom Growing Kit Instructions

Reishi is a slow-growing mushroom, producing one crop per year.  With this kit, you will watch the mycelium slowly develop and produce otherworldly waxed red brackets. Your Reishi will grow inside the fruiting bag which is fitted with a special micro-filter patch, allowing some gas exchange but inhibiting moisture loss and competing organisms. 

Each species of mushroom is a different growing experience. Even if you have grown mushrooms before, please read the instructions carefully before proceeding. If you run into any problems please see our FAQ.

Step 1: Mycelium Check

Inside of this box, mycelium has has been happily breaking down the organic growing medium and converting it into energy.


Open the box and remove the bag of reishi mycelium and growing medium from the box. DO NOT OPEN THE BAG but instead inspect the block through the bag to determine what stage the mycelium is at.

What colour is it?


Brown or brown & white =

needs more time in a warm / dark location


Almost entirely white =

Ready to move on to step 2

Yellow & red patches =

Ready to move on to step 2

If your mycelium needs more time to develop, return it to the box and place it in a warm location - over 15°C and NO MORE THAN 25°C. Check it once a week until it is almost completely covered with dense white mycelium.


Please note that red and /or yellow patches are normal characteristics for mature Reishi mycelium.


If you are not ready to move on to step 2 but your block is, you can store it in the fridge for up to a month.

Step 2: Initiating Fruiting

Cut open the top of the bag just under the seal along the top edge.  Be careful to maintain its sterile environment as much as possible. WITHOUT BREATHING INTO THE BAG, inflate the bag to create space for your mushrooms to grow and carefully reseal the top edge using sellotape.

We demonstrate how to do this in the video below.

Step 3: Finding an Ideal Location

Reishi grows best when it is warm, out of direct sunlight and located somewhere where it will remain undisturbed. It is a slow-growing mushroom, producing one crop per year.


Your reishi will grow inside the fruiting bag which is fitted with a special microfilter patch, allowing some gas exchange but inhibiting moisture loss and interference from competing organisms. 

  • Find a spot in your house with indirect sunlight where your reishi can remain undisturbed for a long period of time. A temperature reading between 16°C-27°C is ideal.

  • We recommend placing your block in the box to keep it upright. This will decrease the chance that it will fall over.

Fat Fox image take 2.jpg

Placing your block upright in your box will decrease the chance that it will be disturbed while growing.

Step 4: Growing 

Over the coming months, your mushrooms will begin to grow from the top of the growing medium inside the bag. As they grow, the mushrooms will search for any available oxygen and grow in an 'antler' formation. Your mushrooms may also climb up the sides of the bag, so be careful not to disturb it. Disturbing the bag can result in it aborting the growth of your first mushrooms and needing to start again.

In nature, reishi mushrooms are a perennial bracket fungi. This means that they grow over the course of several years. They are among the slowest growing mushrooms, and sometimes take 4 months (depending on environmental conditions) before the young caps even start to emerge. Once they do, they often start off as lumps and bumps on the top of the block and sometimes clinging to the wall of the bag as they climb upwards towards more oxygen rich environments. Try not to disturb them by moving the bag as they can be easily damaged during this stage and may need to start over again.


Over the course of the first year you should expect to have a Reishi mushroom ready to harvest. If you leave it for longer it may grow bigger!


Want to try an alternative to growing your Reishi in the bag? See our FAQ for a solution that will give your mushroom more room to grow!

Common Questions

  • There are some green spots on my reishi block. Is this a problem?

As your mushrooms grow, you will likely notice small patches of competing organisms (usually green) on the surface of your block. This is because non-sterile air has entered the bag when it was inflated. It will not affect the growth, health or quality of your mushrooms and can be cleaned off after harvest.

  • My reishi mushroom has gotten large. I really want to see what's going on! Can I open the bag?


While we generally suggest that you grow your reishi mushroom inside of the bag to keep the humidity up, if you're just itching to know what's going on inside, you can cut open the top of the bag once your mushroom has reached between 10-20mm. Add 1/2 inch of water into the bottom of the bag to keep the humidity up. Without added moisture your mushroom will dry out and stop growing prematurely. If you'd like to cut the plastic bag away completely, see our FAQ on how to give your reishi more room to grow.

Different Options For Growth

  • Once the reishi has climbed 10-20cm tall you can cut the top of the bag off to expose them to the fresh air and help them form bracket, or you can leave them sealed inside the bag to maintain the antler formation (be aware that if you leave the mushrooms in the sealed bag, they may punch through the filter patch or through the top of the bag. This is not a problem, but you will have to follow the instructions below to prevent spores getting all over your house!)

  • If you choose to cut open the top of the bag, brackets will begin to form at the ends of 'antlers'. With the bag now open you will need to add water to your reishi block to maintain a humid growing environment. Try to keep 2cm of water in the bottom of the bag at all times. At this time your reishi should be moved to a location where its spores will not be easily breathed in. This is best practice as breathing in large volumes of spores can be hazardous to your health.


Antler formation


Brackets have formed on the end of the antlers. 


Reishi mushroom growing through the filter patch

Step 5: When to Harvest

As the brackets grow, their rims will turn white. Once the rims have turned from white to orange and finally to red, the mushrooms are ready to harvest!

The rim is typically white during times of accelerated growth, which often occurs during warmer months. Once the rim of the cap becomes orange/brown this is normally an indication that the cap is no longer rapidly growing.


You can also feel the weight of the block. If the block feels very light, this is often a clear sign that the Reishi mushroom is unlikely to grow any larger.

TIP: It's best to wait until ALL of the tips of your reishi brackets or stag horns have turned completely (and quite dark) red before you harvest rather than attempting to harvest a bit at a time. It can be hard to wait, but you want to give your reishi the chance to grow to its full size before harvest.


The edges of the mushroom are still white. It is still growing bigger.


The edges of the mushroom have turned red. This means it has stopped growing and is ready to harvest. 

Step 6: Harvest
  • When your Reishi are ready to harvest, carefully cut away all of the plastic bag.

  • Remove the fruiting bodies from the block of growing medium.​

Step 7: How to Prepare your Mushrooms

Fresh reishi are very tough, which means eating them directly is impractical. You can chop up fresh Reishi mushroom and boil in water for 20-30 minutes to make a tea or prepare your own tincture.

Step 8: What to do with your kit when it's finished producing mushrooms

Did you know that fungi play a key role in storing carbon? Trees and plants remove carbon from the atmosphere and fungi break down plant waste to create new carbon-rich soil. Clean air, healthy soil and delicious mushrooms: just one of the many ways fungi are incredible!

Once your kit has finished flushing, discard the bag in the general waste. You can now recycle the box and additional packaging and compost the block. Alternately, plant it in the garden to see if it will gain a some energy and produce one last seasonal crop for you! Simply dig a hole in a shady spot, bury the block and cover it over with around 5cm of soil. Water it occasionally to keep the soil moist. 


We hope you've enjoyed growing your Reishi mushrooms!

We're passionate about sharing the diversity of the fungi kingdom & making more  of its edible & medicinal delights easy to grow. Want to try another strain or learn how to cultivate mushrooms? See our full range of mushroom growing kits and cultivation workshops!

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