Red thread disease (Laetisaria fuciformis) is a common lawn disease. It affects both residential lawns and sports fields such as golf courses, where it mainly occurs between spring and fall. Although its visual appearance can be worrying, it does not generally cause the death of the lawn. This fungal disease often reflects an imbalance in the management of lawn care. Fortunately, practices and solutions can prevent and treat this disease.
Identity card of the red thread of the lawn
Red thread disease belongs to the fungal diseases and occurs mainly on grasses, plants widely used for lawns. Two fungi are responsible for it: Laetisaria fuciformis and Limonomyces roseipellis . These pathogens find a favorable terrain in conditions of high humidity, combined with temperatures above 16 ° C. This favorable climate often extends from March to November.
Biological factors and propagation
Red thread disease develops under specific conditions that favor its rapid spread. Several elements influence its occurrence:
- Excessive humidity : the presence of dew, fog or nighttime watering helps maintain a humid environment conducive to sporulation and germination of spores.
- Mild temperatures : This fungus thrives as soon as the temperature exceeds 16°C, creating favorable conditions between spring and autumn.
- Vulnerability of young lawns : Newly planted or establishing lawns are particularly susceptible to this disease.
- Nitrogen deficiencies : Lack of nutrition weakens plants, and nitrogen plays a key role in strengthening grasses against disease.
- Thatch build-up : A thick layer of undecomposed organic matter prevents roots from receiving sufficient water, air and nutrients, making the lawn more vulnerable.
What are the symptoms of red thread in lawns?
Red thread on lawns is characterized by diffuse spots that gradually spread . These yellowish or brown areas widen and take on a characteristic pink or red hue, especially in wet weather. On examination, red filaments or clumps of mycelium can be seen on the affected blades of grass. The leaves begin to discolor at the tips, before drying out.
Although spectacular, this disease has only an aesthetic impact and does not affect the survival of the lawn. Plants temporarily stop growing in infected areas, but they can recover if conditions become favorable again. However, if nothing is done, these lesions compromise the uniform appearance of the lawn and make it vulnerable to other stresses.
Diagnostic et observation
To identify this disease, regular observation of the lawn is necessary, particularly between March and November , a period when conditions are favorable for the development of the fungus.
It is rare to confuse this disease with other lawn diseases, as its symptoms are quite characteristic. A careful inspection of the grass blades in the affected areas can confirm the presence of red filaments or mycelial structures. The areas to monitor first are those where the lawn seems less dense or where water tends to stagnate after watering.
Cultural methods to prevent red thread
A proper preventative approach can significantly reduce the risk of red thread and maintain a vigorous lawn. Here are the actions to prioritize:
- Nutrient management : apply balanced fertilizers to avoid deficiencies, ensuring adequate nitrogen supply.
- Seed diversity : sowing a mixture of varied grasses helps limit the risks associated with monocultures, which are often more susceptible to disease.
- Reducing thatch : Scarifying regularly in spring and autumn improves the circulation of water, air and nutrients while limiting the accumulation of organic matter.
- Soil aeration : Coring is an effective practice to stimulate rooting and optimize lawn health.
- Watering management : prefer morning watering to limit prolonged humidity during the night, while adopting spaced but abundant waterings to strengthen the roots.
- Equipment hygiene : Thoroughly cleaning mowing tools after use helps prevent the spread of spores to other areas.
- Mowing practices : Maintain a cutting height of 5 to 10 cm and limit the frequency of mowing to reduce stress on plants.
Agrobiotop solutions against red thread disease in lawns
At Agrobiotop, we develop natural products and biocontrol solutions for lawns in green spaces, communities, sports fields and golf courses. If you need an expert on a problem such as the common thread of lawns, contact us .
For soil improvement (aeration, decompaction, prevents thatching) :
Our products against lawn diseases (red thread, dollar spot, anthracnose, pythium, rust, etc.) :
Our biostimulants for your lawns (act as a first line of defense against diseases and pests) :
