How much light do mushrooms need to grow?

Reishi mushrooms

Mycelium requires a certain level of light to develop mature fruiting bodies. While some growers prefer to use LED lights at 12-hour intervals, others believe that indirect sunlight from a window is enough.

Some mushroom species do not require light at all to grow, such as e.g Psilocybe Albino prefer it to be almost completely dark for a high yield. Others, such as the psychedelic Psilocybe Cubensis (Wizard naked hat), requires plenty of light to develop healthy, mature fruit bodies. That said, there are differing opinions on how much light mushrooms really need. Keep reading to find out everything you need to know about lighting for your next mushroom production!

There are different opinions on what kind of lighting works best for edible mushrooms, medicinal mushrooms or magic mushrooms.
Some growers prefer to use special types of LED light for growing mushrooms, others choose to use nothing but natural daylight. While the mycelium may not need light to grow, it would be a mistake to assume that fungal fruiting bodies don't either. Whether the light is natural or artificially generated, it is believed that some illumination is necessary for the fungus to complete the fruiting process and guide the fruiting body's growth direction.

cultivation of mushrooms

Some mushroom growers prefer to use fluorescent tubes as lighting to grow mushrooms, and others prefer the more modern and efficient LED lighting. Using artificial light guarantees that mycelium has access to the light it needs even in the absence of natural daylight.

When choosing which grow lights If you're looking to grow mushrooms, the primary considerations should be the lamp's light intensity, spectrum and heat output. Ideally, mushrooms are best suited to a colder light that leans towards the blue end of the spectrum, such as "daylight" fluorescent or LED lamps that emit light in the 6,000-7,000 Kelvin range.

Also, it is strongly recommended to avoid using incandescent bulbs for growing any kind of mushrooms as they emit a warm light of around 2700-3500 Kelvin along with a lot of heat radiation which is bad as mushrooms thrive best in cold rooms.

Many mushroom growers have stated that they can produce healthy and beautiful mushrooms with only natural light, if you make sure that the mushrooms are not exposed to sunlight at any time and a high humidity can be maintained at all times.

Mycelium apparently only requires a minor amount of light form knowing which direction to grow and set its fruits. Placing your terrarium or grow tent somewhere where it can get a healthy amount of indirect daylight can be good enough for most mushroom species.

Overall, your mushrooms will require some sort of light source to set fruiting bodies. Don't expect your mushrooms to just grow in the dark!

mushroom cultivation guide

How much light do mushrooms need?

Mushroom growers have different opinions on the subject.
Some growers rely on a fixed schedule of 12/12 lighting, others prefer to give their mushrooms much less light.
A 12/12 schedule ensures that mushrooms have a healthy amount of light to grow. A lot of light is probably unnecessary and the fruiting process can just as well be completed with much less.

Depending on the intensity of the light you use, it can even be harmful to expose your mushrooms to 12 or more hours of artificial light per day.
Lights measuring below 7,000 Kelvin should be fine to leave on for longer periods of time. If you're worried about your light being too intense or burning your mushroom block, you can safely limit the light to 3-4 hours a day.

Lighting distance from the mushroom block

It is always important to avoid excessive heating. Placing your lights too close to your terrarium or mycelium can result in overheating or even burn damage, damaging your mushrooms or preventing fruiting bodies from fully germinating. Remember to leave some space and watch closely for burn damage, especially if you are using particularly intense grow lights.

UV light turns mushrooms into vitamin D bombs

Fungi produce large quantities D vitamin, when illuminated with ultraviolet light. This discovery could make mushrooms a big hit with vitamin D-starved Scandinavians.

Links to further information on growing mushrooms/mycelium

Guide to medicinal mushrooms

Tips for growing mushrooms in the garden