Why is chemical control ineffective against fairy rings?

Chemical control is ineffective against fairy rings primarily because the fungus associated with fairy rings typically grows deeply into the soil. This extensive and often deep-rooted growth of the mycelium makes it difficult for fungicides to penetrate effectively and reach the target organisms. Since the active parts of the fungus may be located well beyond the reach of surface applications, any chemical treatment may not have a significant impact on the underlying mycelial networks.

While there may be instances where fungi have some resistance to fungicides, this is not the main reason for the ineffectiveness in addressing fairy rings. The cost of fungicide applications could be a consideration but is less relevant than the structural challenges posed by the fungus's growth pattern. Rapid growth can contribute to the visibility of the issue but does not directly correlate with the effectiveness of chemical control measures as much as the depth of growth does.