Book 24, Question 66
Why do mushrooms sometimes grow in a circle called a fairy ring?
A fairy ring is a circle of mushrooms in a lawn or forest. It starts from one spot where a fungus grows underground from a single spore. The threads spread outward in every direction. The oldest threads in the middle die, so the living fungus is a growing ring, and mushrooms pop up along its edge.
More fun facts
- A fairy ring is a fungus colony that can make a circle of mushrooms or dead grass in a lawn.
- The fungus spreads slowly outward through the soil, so the ring grows bigger over time.
- Grass right next to the ring of dead grass can look greener than usual.
- The fungus threads repel water, so grass in the ring can dry out and die in dry weather.
- Some fairy rings grow about 75 centimeters a year, while others grow only a few centimeters.
- Fairy rings in France about 800 meters across were estimated to be around 700 years old.
Sources: rhs.org.uk, National Institutes of Health
Questions kids ask
Why are fairy rings round?
The fungus grows outward evenly in all directions from where it started, making a circle.