Rust is a common foliar disease of turf. It is caused by various fungi, usually Puccinia or Uromyces species. Infected areas may produce huge numbers of air-borne spores. When walking your lawn you will notice the brown from the rust spores covering your shoes.
Typical symptoms of lawn rust include;
Feed the lawn regularly during the growing season to maintain vigour
Avoid high nitrogen fertilisers in the autumn, as the resultant lush growth may be more prone to attack by rust and other diseases such as Fusarium patch
Mow regularly to reduce the number of affected leaves, removing the clippings
Improve air circulation by selective pruning of overhanging trees and shrubs and good aeration.
There are no fungicides for the control of rust on lawns. Chemical control of rust is usually unnecessary as the symptoms are temporary. Even lawns that are heavily infected in autumn will usually produce healthy growth by early summer of the following year.