What causes fairy rings to appear?
Fairy rings are the result of certain types of fungi forming fungal threads in the soil that the turf is laid on. The most common fungus to cause fairy rings is Marasmius Oreades. The threads that form are very densely packed and normally reach down so soil depths of around 20cm although they have been known to reach up to about 40cm. The effect of these tightly packed threads on the lawn is to effectively starve the grass roots of both water and nutrients by inhibiting root growth and preventing water uptake. The resulting lack of water will effectively kill the grass in badly effected areas of the lawn and so yellow / brown patches can appear. Bare patches of soil may appear on the lawn where the grass has been dead a long time.
