How To Grow Reishi Mushrooms

Reishi mushrooms are easy to grow and an exciting option for those interested in growing their own medicine. While they’re a bit slower-growing than other species, they make up for this by being aggressive colonizers tolerant of warm temperatures. They are also extremely beautiful, and sometimes even cultivated as ornamental art pieces! 

What is Reishi?

Reishi is a medicinal mushroom that has been highly valued in China for thousands of years, where it is considered a “longevity herb” that improves human health and slows aging. In the past half-century it has been the research topic of hundreds of scientific papers examining its potential health benefits, including numerous clinical trials.

Health Benefits of Reishi Mushrooms

Research has been largely focused on its immune-boosting properties, but it also suggests Reishi may have anti-inflammatory, anti-viral, anti-cancer, and antioxidant properties. It has also shown potential to help improve sleep, protect the liver, and maybe even improve the regulation of blood sugar.

Can You Eat Reishi Mushrooms?

Reishi is unlike other commonly cultivated species as it is a tough-woody polypore that doesn’t really lend itself well for culinary purposes. Apart from being bitter (thanks to its health-promoting compounds), it is also just too hard to eat. To really get the most out of their medicinal properties, the mushrooms must undergo an extraction process.

Extracting Reishi Mushroom

To extract Reishi mushroom it is typically reccomended to do a double-extraction tincture or an extracted powder. Extracted powders can be easily made by cutting your Reishi into slices, boiling them in a bit of water for 2-3 hours, and then dehydrating the boiled mushroom along with any liquid. Once dried, powder it all together with a blender or coffee grinder. This powder can now be consumed directly, added to smoothies, or utilized in many different forms to receive the health benefits.

What do Reishi Mushrooms Look Like?

In its appearance, Reishi mushrooms have a glossy, reddish-brown cap and a woody texture. It sometimes goes by the name lacquered or varnished conk because of this. They can be incredibly beautiful, and are sometimes grown in an eye-catching “antler” form which can be utilized as an ornamental centerpiece.

Types of Reishi

Taxonomically speaking, Reishi is considered complex and poorly understood. There are many different types of mushrooms commonly called Reishi, encompassing what is likely dozens of species. While the name Ganoderma lucidum has been commonly utilized around the world, the truth is that dozens of similar mushrooms go under this name. The true Ganoderma lucidum is only native to Europe, while those utilized in traditional Chinese and Japanese medicines are different species. The name Ganoderma sichuanense is now utilized for some of the most medicinally valued species in Asia.

While many different species are distributed under the name Ganoderma lucidum, the good news is that they are all quite similar. They largely contain the same bioactive compounds, and they do differ much in cultivation technique. This said, it is a great idea to ask your producer about their experience with their strain to determine optimal growth temperatures.

Growing Reishi Mushrooms at Home

Nuances of Reishi Cultivation

Before moving forward with any technical details, let's discuss some of the nuances involved in the cultivation of Reishi Mushroom

• Growth Form: Reishi can grow in two forms, the antler form or the conk form. The environment's CO2 levels influence this. Elevated CO2 conditions lead to antler-like formations that grow upwards. Certain strains are also valued for their ability to produce antlers.
  
  
• Slow Growth: Reishi takes longer to fruit than other mushrooms. While some mushrooms, like oysters, can be harvested in 1-2 weeks, Reishi takes a minimum of 6 weeks and could take up to twice that depending on your strain, substrate, and conditions.
  
  
• Warm Loving: Reishi loves warm and elevated temperatures compared to other mushroom species. It’s a great option for cultivation in hot climates, or during the summer season.
  
  
• Tolerance: Reishi is a resilient species and can tolerate higher CO2 levels and fluctuations in environmental conditions compared to other mushroom species.
  
  
• Strain Selection: There are many different strains of Reishi out there, which in many cases, represent completely different species. For this reason it is important to choose a recommended strain that will be suitable for your climate. If you are seeking to use them for medicinal properties, consider sourcing a strain valued for producing higher quantities of bioactive compounds.

Note: The taxonomy of Reishi is complex, as the scientific name Ganoderma lucidum has been historically applied to species around the world. The true Ganoderma lucidum species is from Europe, whereas all Asian cultivars are actually distinct species such as Gandoerma sichuanense. Almost all of these related species, known as “Varnished Conks” or as part of the Ganoderma lucidum complex produce similar bioactive compounds, albeit at different quantities.

Cultivation Method

If you are just getting started with mushroom cultivation, we recommend you check out our introductory series. Here will cover the quientestial process of cultivation, and introduce you to all the most important steps; Substrate, Pasteurization/Sterilization, Spawn, Inoculation, Incubation, and Fruiting.

Substrate for Reishi

Reishi mushrooms are cultivated on hardwood sawdust. This includes Oak, Maple, Walnut, and many other species. You can source your sawdust from local mills or cabinetry makers, or purchase hardwood fuel pellets. This sawdust can be utilized alone, or supplemented with bran or soy hulls.

Once you have your raw materials ready you want to hydrate it to about 65%. Avoid having it too wet as this can lead to contamination. If you squeeze the substrate with the palm of your hand, no more than 1-2 drops should come out.

Once the substrate is hydrated, you can fill your heat-resistant polypropylene grow bag. Most growers make 5lbs blocks but you can make them a bit smaller or bigger depending on your needs. Make sure not to overfill them so that the top can be easily folded and closed. If you want to fruit in-bag for antler Reishi, only fill the bag 1/3-1/2 of the way to allow plenty of room for the growth of the antlers. Once the bag is filled, fold the top of the bag underneath the block.

Pasteurization/Sterilization

Now it’s time to “clean” the substrate of any potentially harmful microorganisms. If you’re growing in unsupplemented substrate you can get away with a simple pasteurization, but if you supplemented your substrate you will need to conduct proper sterilization. If you’re using hardwood fuel pellets, these can often simply be pasteurized by hydrating them with boiling water. Check out our full-length article on Pasteurization/Sterilization for all the details you need to know.

Inoculation

For inoculation, you’ll be needing some high quality spawn. You can make your own, or purchase it from a trusted producer. You can read all about spawn and how to make it here.

The process of inoculation simply involves mixing your substrate with your spawn. If you’re using supplemented substrate it’s recommended to do this in front of a laminar flow hood or inside a still-air-box.

For inoculation, you’ll simply want to empty your grain onto your substrate. Use about a 10-20% ratio of spawn to substrate. Afterwards, close the bag, either with an impulse sealer, a clip, or even a zip-tie, ensuring no air can enter. Once properly sealed, mix the grain spawn with the substrate by shaking the bag. Mix as evenly as possible. For more details see our full inoculation article.

Incubation

Incubation is the period when the mycelium (the vegetative part of the fungus) colonizes the substrate. Reishi is considered a relatively slow grower, taking at least 3-4 weeks for proper colonization. In some cases, it may be quicker so it’s important to keep an eye on your block.

Reishi typically likes warmer temperatures between 70-80°F (21-27°C) for incubation. These numbers can vary greatly by strain. Make sure to inquire about your strain from your provider.

You’ll know the incubation process is done once the substrate is white and fully colonized and white. Reishi mycelium also releases a red liquid which accumulates in certain pockets of your bag. In many cases, you can wait until the fruiting block starts producing primordia before taking it to fruiting.

See our full incubation guide here.

Fruiting Reishi Mushrooms

Reishi can be fruited to produce the classic kidney-shaped conks or the finger-like antlers. Depending on your fruiting conditions, you can manipulate it to grow in either form.

Considerations For Fruiting

• Draining: As mentioned, Reishi mycelium produces a Reddish liquid which accumulates around the substrate. Many growers like to drain this liquid by cutting the edges of the bag and simply letting the liquid drain out.
  
  
• Moisture: About 85-90% humidity is ideal for fruiting body development. This being said, Reishi is pretty resistant to fluctuations in this and will do fine as long as the substrate is well hydrated.
  
  
• Temperatures: Reishi likes it warm and fruits best at temperatures between 70-80°F (21-27°C), although it handles temperature fluctuations pretty well. Exact temperature preference will vary greatly depending on the strain.
  
  
• Lighting: Indirect light is beneficial for the fruiting stage and helps produce the darker pigments Reishi is known for. Fruiting bodies will actually grow towards the light, so it’s possible to manipulate the growth structure simply by altering the lighting.

If you're curious to learn more about fruiting check out our complete guide here.

Harvesting Reishi Mushrooms

Harvesting of Reishi occurs once the white-growing tip of the fruiting body is greatly reduced in size and is only about 1 cm in size. This is right before complete maturity and the maximum release of spores. Mushrooms harvested at this stage will cause a good yield and quality.

To harvest, you can use a scalpel, sharp knife, or even pruning scissors. Plucking will often result in you damaging the fruiting block, which may be able to be fruited for a second or third time.

Other Reishi Cultivation “Teks”

Log Cultivation: Reishi mushroom can be easily cultivated in logs for anyone interested in growing outdoors. While they may take 8-12 months to bear fruit, they can fruit for several years if properly maintained. We’ll write up a whole guide on log cultivation in the future.

Monotub: Monotubs aren’t typically used for Reishi, but some growers have had good success. Simply disinfect your monotub and add your pasteurized substrate and spawn to it, then let it do its work!

Buried Log Cultivation: In Asia, Reishi blocks are often fruited directly from the soil utilizing buried logs. This process involves sterilizing blocks of wood, inoculating them, letting them colonize, and then burying them in greenhouses. This same method can be done with colonized sawdust blocks. This works great for greenhouses, or places with humid summers.

MycoMaterials: Many people utilize Reishi mushroom mycelium as a myco material. Colonized substrate can be broken up, placed into a disinfected mold, and allowed to incubate. Over time the mycelium fuses and makes a solid piece of material in any shape you’d like. Some growers have success utilizing spent mushroom blocks after harvesting.