Organic Control of Fairy Rings in Lawns

What Are Fairy Rings?

Fungal mycelium growing in circle, decomposing organic matter. Three types: dark green ring (nitrogen release), dead ring (hydrophobic soil), mushroom ring. All same fungus.

Organic Treatment

Mix 4 tsp baking soda + 1 tbsp horticultural oil (or cooking oil) per gallon water. Spray ring and 1 ft inside/outside until saturated. Repeat in 7–10 days if needed. Rarely requires third application.

Why It Works

Baking soda disrupts fungal cell walls. Oil improves coverage and penetration. Safe for grass, pets, microbes.

Cultural Prevention

• Reduce thatch (vertical mow if >½ inch).
• Core aerate annually.
• Balanced fertility (avoid high nitrogen spikes).
• Deep, infrequent watering.

Lawn Service Warning

Chemical spray services kill beneficial fungi that compete with fairy ring fungus. They create dependency. Organic program builds competitive soil biology.

If Caused by Buried Wood

Dig out stump/roots if accessible. Otherwise, treat as above—fungus will finish decomposition eventually.