Fusarium – What is it?

What is Fusarium?

Fusarium patch, also referred to as snow mould and with the scientific name of Microdochium nivale, is a lawn disease commonly responsible for brown patches in lawns, particularly in autumn or during mild spells in winter.

The disease can be extremely damaging and difficult to control. It can be troublesome to a vast range of grass species such as ryegrass, bents, fescues and annual-meadow grass in particular.

The disease begins as small yellowish dying patches of grass that over time will expand and turn brown. Occasionally white cotton wool-like fungus will form at the tips of the grass blades.

When am I likely to see Fusarium?

Fusarium can attack at any time of the year however you are most likely to see an outbreak during autumn, winter or early spring. It typically develops during periods of high pressure, such as wet-mild spells. Lawns that lack sunlight or struggle to dry out can be very susceptible.

The disease can be very noticeable once snow has thawed following a prolonged period laying on the ground, this is where it gets its name Snow Mould from. Also, you may see fusarium develop on lawns that have been covered in leaves for a long period of time.

How do you prevent Fusarium?

Generally the best defence against fusarium is to have a healthy lawn. This means having good provision of light, air, food and water. Like most fungi, fusarium relishes damp, enclosed, still, low light conditions so if it’s possible to improve any of these, this will improve disease resistance.

Fungicides are available to help prevent the development of fusarium however these tend to be very expensive and require regular repeat applications.

Fusarium is a disease that is caused by nature and nature is also the best remedy in most cases. A change in weather conditions to colder temperatures, higher and longer light levels and greater air movement usually corrects the problem.

Fighting Fusarium, In Summary:

  • Maintain a healthy lawn including regular aeration and scarification, which will help the lawn dry faster following heavy dews or rainfall.
  • Remove heavy dews from the lawn using a brush or cane.
  • Improve growing conditions by increasing light and airflow by cutting back overhanging trees and shrubs.
  • Avoid using high nitrogen fertilisers late in the year.