Do Mushrooms Need Light to Grow?
Unlike most plants, mushrooms do not rely on light for photosynthesis. Instead, they grow from fungal mycelium, which feeds on organic matter like wood, compost, or soil. However, light does play a role in mushroom development, particularly in triggering fruiting and shaping their growth.
If you're wondering how much light mushrooms need, whether they can grow in the dark, and what type of lighting works best for indoor mushroom cultivation, this guide will cover everything you need to know!
Do Mushrooms Need Light to Grow?
The short answer is:
✅ Mushrooms do not need light for mycelium growth (colonization phase).
✅ Mushrooms need indirect light for proper fruiting (mushroom formation).
Mushrooms are fungi, not plants, meaning they do not perform photosynthesis. Instead, they obtain nutrients from organic material. However, certain types of mushrooms respond to light as a trigger to start forming fruiting bodies (mushrooms).
The Two Growth Stages of Mushrooms
Mushrooms go through two major growth phases, each with different light requirements:
1. Mycelium Colonization Stage (No Light Needed)
🌿 Mycelium, the root-like structure of fungi, spreads through the growing medium in complete darkness.
🌿 This stage usually lasts 2-4 weeks depending on the mushroom species.
🌿 Light exposure is unnecessary and does not speed up growth at this stage.
2. Fruiting Stage (Light Required)
🍄 Once mycelium fully colonizes the substrate, mushrooms need low-intensity, indirect light to begin fruiting.
🍄 Light acts as a signal to mushrooms that they have reached the surface and it is time to form fruiting bodies.
🍄 Too much direct light or darkness can cause malformed mushrooms.
Why Do Mushrooms Need Light During Fruiting?
Even though mushrooms do not use light for energy, they respond to it for several reasons:
1. Triggers Fruiting
💡 Light signals to mycelium that it has reached the surface and should start forming mushrooms.
2. Helps Mushrooms Grow in the Right Direction
📏 Mushrooms grow toward light to find fresh air and release spores effectively.
3. Prevents Malformed Growth
🚀 Insufficient or incorrect lighting can lead to thin, elongated mushrooms that struggle to produce spores.
How Much Light Do Mushrooms Need?
Most mushrooms thrive under low-intensity, indirect light for about 8-12 hours per day.
- 🌑 Mycelium stage: No light needed
- 💡 Fruiting stage: 8-12 hours of light per day
Mushrooms naturally grow in shaded forests with indirect sunlight. Mimicking this with LED, fluorescent, or ambient indoor lighting works best.
Best Types of Light for Growing Mushrooms
Since mushrooms do not photosynthesize, they do not require specific wavelengths of light like plants. Instead, they need soft, indirect light.
✅ Best Light Sources for Mushrooms:
✔ Fluorescent lights (cool white or daylight bulbs)
✔ LED grow lights (low-intensity)
✔ Natural indirect sunlight (not direct)
❌ Lights to Avoid:
🚫 Strong direct sunlight – Dries out the substrate and stresses mushrooms.
🚫 High-intensity LED grow lights – Unnecessary since mushrooms don’t need high-energy light.
🚫 HPS or incandescent bulbs – Produce too much heat.
Best practice: Place mushrooms in a room with a nearby window or use a low-intensity grow light for 12 hours a day.
Which Mushrooms Need Light?
Mushrooms That Require Light to Fruiting:
🍄 Oyster Mushrooms – Require indirect light for proper fruiting.
🍄 Shiitake Mushrooms – Benefit from indirect daylight or artificial light.
🍄 Lion’s Mane – Needs consistent lighting for even growth.
🍄 Enoki Mushrooms – Can tolerate low-light but benefit from minimal exposure.
Mushrooms That Can Grow in Complete Darkness:
🌑 White Button Mushrooms – Can fruit in near-dark conditions.
🌑 Portobello & Cremini Mushrooms – Do not require much light.
Common Mistakes When Using Light for Mushrooms
🚫 Too much direct sunlight → Can dry out the substrate and stunt growth.
🚫 Not enough light → Can cause long, stretched mushrooms with weak stems.
🚫 Wrong light source → Incandescent bulbs produce heat, harming mushrooms.
Solution: Use soft indoor lighting for 8-12 hours a day in a controlled environment.
FAQs About Mushrooms and Light
1. Can mushrooms grow without light?
✅ Yes! Mycelium colonizes best in complete darkness. However, mushrooms need some light to trigger fruiting.
2. What happens if mushrooms don’t get light?
Mushrooms may struggle to grow or become deformed, with long, weak stems and small caps.
3. Do mushrooms grow faster with more light?
No, increasing light exposure does not make mushrooms grow faster. Proper temperature, humidity, and airflow are more important.
4. Can I use LED grow lights for mushrooms?
Yes! Low-intensity LED lights (daylight or white) work well. Avoid high-intensity plant grow lights.
Final Verdict: Do Mushrooms Need Light?
💡 Yes, but only during fruiting!
✔ Mycelium stage: No light needed – grows best in darkness.
✔ Fruiting stage: Low-intensity light needed – triggers mushroom development.
For best results, place mushrooms in a room with indirect natural light or use a soft LED light for 8-12 hours per day. Avoid strong, direct light to prevent drying out.
🚀 Want to grow mushrooms at home? Invest in the right lighting and setup for optimal yields!
