Lawn Diseases

There are numerous diseases than can affect grass. Below are some of the most common ones. Most diseases are spread by spores and relate to lawn and soil conditions.

Red Thread

This increasingly common disease usually occurs in the late summer after periods of warm weather with heavy rainfall producing conditions of high humidity. Lawns with poor fertility are highly susceptible to red thread disease. The grass will gradually show signs of browning off with brown patches of dying grass appearing and you will see red threads on the grass stalks. High humidity, poor fertility and or blunt lawn mower blades smashing the grass ends are usually the cause of red thread. Serious cases may require an application of fungicide to control the disease. The lawn usually recovers in 2/3 weeks after treatment.

Fungal Pathogens

These can cause various turf diseases. Fine-leaved grasses such as bents and fescues are more susceptible than rye grass species.

Snow Mould

Snow mould occurs at cool times of the year. Brown patches appear followed by fluffy white growth.

Fusarium Patch

Yellow brown patches in your lawn usually, but not exclusively, during autumn and a white grey coloured mould particularly in shaded areas are indications of fusarium patch. Lawns receiving too much nitrogen feed are susceptible, as are lawns on compacted soil. Aerating and ensuring the grass receives a balanced fertiliser feed program can cure fusarium patch. Serious infections will require treatment with fungicide.

Brown Patches

Can be caused by a variety of things so a proper assessment is need before treatment selection.

Dry Patch or Hydrophobic Dry Patch

During periods of dry weather a fungus builds up around the soil particles and will have an effect of repelling the water droplets in the soil. A severe case of dry patch will result in the soil almost being unable to absorb water and any rain will run across the surface of the soil like rain on a glass plate. The grass suffers as moisture is not reaching down to the roots. Aerating your soil by spiking or hollow tine aeration combined with an application of a wetting agent to tackle the fungal disease will improve the water absorption properties of the soil and benefit the grass.

Fairy Rings

Easily identified by a circle or ring of lush green growth. Depending on the type of fungus causing the fairy ring there may be an area of dead brown grass in the middle of the circle.

Slime Moulds

Slime moulds usually appear on dead grass as they feed on dead organic matter and cause no real harm.