Fairy rings are typical in hot, dry weather. The drier the soil the more air it contains and the fairy ring fungi thrive in well aerated soils. As turf loses its colour in the dry conditions the fairy rings stand out much more as dark green rings against a light green background. Some fairy rings are cosmetic only and do not harm the grass. However, some make the soil water repellent and cause dry patch. Others are suspected as attacking the grass directly.
How can we treat them?
- If there is no harm to the grass other than the visible ring you can darken the whole green by applying a little fertilizer or iron. This will make the fairy ring less visible.
- Sometimes superficial fairy rings (thatch fungi) can degrade the thatch to a point surface depressions are caused. These can be levelled with top dressing.
- If the rings are particularly troublesome, they can be treated with wetting agents according to the following wetting agent procedure:
Spike the rings to a depth of the mycelium in the soil plus 2cm. Holes should be very close together, the more the better and should be made 10cm either side of the ring as well as in the green ring itself. This is because mycelium spreads underground wider than the visible ring on the surface. Irrigate the turf for 5 mins and apply wetting agent (curative wetting agents recommended) at standard label rates and leave to stand for 1 hour. Repeat this process to ensure the ring has had a thorough soaking with wetting agent. Irrigate/drench using a hosepipe until water floods on the surface, then leave to soak in. This process often but not always works on breaking the water repellency of the fairy ring mycelium. We recommend it is tried in the first instance without fungicide. If the process is only partially successful, repeat as necessary and then afterwards apply a suitable fungicide, applying light irrigation afterwards to wash the fungicide into the core holes.