How can I remove lawn fairy rings?
Q
What are these rings on the lawn and what can I do about them? Simon Wilson, via email
ABad luck! Fairy-ring fungus (Marasmius oreades) has invaded your lawn. To control it efficiently, dig out the affected dead grass to 3ft (1m) deep and 1ft 6in (1∕2m) on either side of the ring. Then replace ‘spoil’ with uncontaminated soil.
The only problem, apart from it being demanding and expensive, is that its roots may have spread beyond the dead circle.
An easier and almost as effective alternative is to aerate the dead patch with a garden fork to a depth of 10in (25cm), then water it with dilute detergent to remove waterproof resins from the soil particles. Rain will then penetrate. Finally, scarify the area and overseed it with a ‘lawn thickener’ blend. Hopefully, new growth will cover the bald ring and the disease won’t recur.