Turf diseases
Plant Diseases
1/20/202512 min read
Turf Diseases, natural traitements
Dollar Spot
Turf Rust: Puccinia and Uromyces spp.






Anthracnose — Colletotrichum graminicola


Red Thread (Laetisaria fuciformis)


Helminthosporium spp. Drechslera spp., Bipolaris spp. and Exserohilum spp.


Dollar Spot
Dollar Spot is a prevalent fungal disease that commonly affects lawns, particularly on golf courses and ornamental turfgrass. Caused by the fungus Sclerotinia homoeocarpa (now often classified under the genus Clarireedia), this disease creates distinct, circular patches of discolored grass, weakening the lawn. Due to its significant impact on the appearance and health of lawns, effective management strategies are essential.
Understanding Dollar Spot Dollar Spot primarily affects cool-season grasses like fescue, bentgrass, and Kentucky bluegrass. These grasses are commonly found on well-maintained lawns and golf courses. The disease is most active during warm, humid periods, often appearing in late spring or early summer.
Factors Contributing to Dollar Spot
Environmental conditions: High humidity, frequent dew, and moderate temperatures favor the growth of the fungus.
Lawn stress: Stressed lawns, such as those that are drought-stressed, nutrient-deficient, or compacted, are more susceptible.
Mowing practices: Frequent mowing at very low heights can weaken the grass and make it more vulnerable to disease.
Symptoms of Dollar Spot Dollar Spot causes small, circular patches of bleached or straw-colored grass. These patches can range in size from a few inches to several feet in diameter. Under humid conditions, a white, cottony growth may be visible on the infected grass blades.
Spread of Dollar Spot The fungus spreads through the production of spores. These spores can be easily spread by wind, water, or mowing equipment.
Preventing Dollar Spot
Proper mowing: Maintain a proper mowing height to promote a healthy lawn.
Watering: Avoid overwatering, as excessive moisture can create favorable conditions for the fungus.
Fertilization: Apply a balanced fertilizer to promote healthy grass growth.
Aeration: Regularly aerate your lawn to improve drainage and reduce compaction.
Thatch removal: Remove excessive thatch to improve air circulation.
Cultural practices: Avoid walking on wet lawns and clean mowing equipment to prevent the spread of disease.
Fungicides: Preventive fungicide applications can help protect your lawn.
Roots and Soils Solutions
For soil aeration (action on felting):
GaiaOxy & GaiaFulfur
For the nutrition of golf courses and sports fields:
GaiaBoost
Treatments for Dollar Spot Disease:
GaiaGuard, GaiaHydra and GaiaClay
Request our protocol against the dollar spot on grasse!
Anthracnose
Colletotrichum graminicola
How to Combat It?
Plant Diseases
Have you noticed yellow or brown patches spreading across your lawn, or areas that seem to be thinning out faster than usual?
Your lawn may be affected by anthracnose disease (Colletotrichum graminicola), a fungal disease that attacks grasses weakened by stress and changing weather conditions. Let's delve into the causes, symptoms, and solutions for effectively combating this dreaded fungus.
If you need assistance in improving your lawn and controlling Colletotrichum graminicola, please don't hesitate to contact us. We have developed natural protocols and solutions to manage and control this lawn disease.
Table of Contents
Description of Colletotrichum graminicola in lawns
Which plants are susceptible to Colletotrichum graminicola?
Conditions favorable to the development of Colletotrichum graminicola
Symptoms of Colletotrichum graminicola
Preventive measures and control methods for Colletotrichum graminicola
Roots and Soils solutions for Colletotrichum graminicola
Description of Colletotrichum graminicola in lawns Colletotrichum graminicola is caused by the fungus Colletotrichum graminicola. This fungal disease primarily targets weakened grasses, especially those affected by high temperatures, drought, or nutritional deficiencies. Typically occurring during the summer months (June to August), Colletotrichum graminicola can also emerge in spring (May) and persist into autumn (September and October). This fungus develops on the surface of leaves and stems, causing lesions that quickly compromise the quality of the lawn, leading to bare patches.
Which plants are susceptible to Colletotrichum graminicola? Certain grass species are particularly susceptible to Colletotrichum graminicola, such as annual bluegrass (Poa annua), bentgrass (Agrostis spp.), and red fescue (Festuca rubra). These varieties, commonly used in gardens and golf courses, are more prone to this fungal infection, especially when subjected to stress.
Conditions favorable to the development of Colletotrichum graminicola thrives under specific conditions. The fungus develops particularly well when temperatures range between 25 and 30 degrees Celsius, combined with high humidity and prolonged leaf wetness. These conditions are exacerbated by compacted soils where water stagnates and roots lack aeration, creating a favorable environment for the fungus. Additionally, improper mowing practices, especially mowing too low, add further stress to the grass. Nitrogen deficiencies also weaken the grass, making it more susceptible to Colletotrichum graminicola, while excessive or late irrigation leaves the grass wet at night, promoting fungal growth.
Symptoms of Colletotrichum graminicola manifests itself through damage that affects both the visual appearance and overall health of the lawn. The main symptoms include:
Irregular patches: Yellow to brown areas appear, often arranged in bands that gradually spread.
Thinning: The lawn begins to lose density, with sparse and weakened areas.
Black growths on stems: Infected stems show dark growths and black spots, which are the fruiting bodies of the fungus responsible for the disease.
Leaf detachment: Affected leaves detach easily due to root rot, leaving the roots in the soil, further weakening the lawn.
Preventive measures and control methods for Colletotrichum graminicola Several practices can ensure proactive and sustainable lawn management to maintain good health and increase resistance to diseases like Colletotrichum graminicola.
Balanced nutrition: Regular and adequate supply of nitrogen (N), phosphorus (P), and potassium (K) strengthens the grass. Deficiencies, especially in nitrogen, make the grass more vulnerable to fungal infections. Applying the biostimulant GaiaB strengthens the resistance of grasses in addition to fertilizers.
Mowing management: Maintaining a cutting height of at least 5 cm helps reduce stress on plants. It is also recommended to avoid mowing when the grass is wet, which limits the dispersion of fungal spores.
Adapted irrigation: To avoid excessive moisture, it is advisable to water the lawn early in the day. This allows the grass to dry before night, thus limiting the risk of fungal infection.
Thatch removal: By removing the layer of thatch on the soil surface, excessive humidity that can promote the spread of the disease is reduced. GaiaOor GaiaP are the main allies for this thatch removal operation on lawns.
Dew removal: On golf courses or very sensitive surfaces, removing morning dew can be a useful practice to reduce the humid conditions favorable to the fungus. GaiaO or GaiaP allows for better soil aeration, thus eliminating excessive moisture on lawns.
Cooling during hot periods: In case of high heat, the application of our Range GAIA helps to reduce heat stress on the lawn.
Request our protocol against the Anthracnose on grasse!


Turf Rust: Puccinia and Uromyces spp.
How to Combat It?
Plant Diseases
Lawns, whether ornamental or for sports activities, are valuable assets that require careful maintenance. Among the diseases that can affect them, lawn rust is a significant concern. This fungal disease, caused by microscopic fungi, can rapidly diminish the aesthetic appeal and vitality of the turf. However, with a thorough understanding of its biology and the implementation of effective control measures, it is possible to minimize its impact and maintain a healthy lawn.
Table of Contents:
What are the Pathogens Responsible for Lawn Rust?
Environmental Factors Favoring Disease Development
Life Cycle and Disease Spread
Symptoms of Lawn Rust
Impact on Green Spaces, Sports Fields, and Golf Courses
Prevention and Control
Roots and Soils Solutions for Lawn Rust Control
What are the Pathogens Responsible for Lawn Rust? Lawn rust is a fungal disease caused by fungi belonging to the genera Puccinia and Uromyces, members of the Pucciniaceae family. These pathogens primarily attack grasses, including common species such as ryegrass, fescue, and bluegrass.
Environmental Factors Favoring Disease Development The development of lawn rust is significantly influenced by environmental conditions:
Temperature: Optimal temperatures for fungal growth typically range between 60°F and 75°F (15-24°C).
Humidity: High humidity, particularly prolonged periods of leaf wetness from dew, rain, or overwatering, creates an ideal environment for fungal spore germination and growth.
Shade: Shaded areas within the lawn tend to remain moist for longer periods, increasing the risk of disease development.
Nitrogen deficiency: Inadequate nitrogen fertilization can weaken the grass, making it more susceptible to disease.
Life Cycle and Disease Spread The fungi responsible for lawn rust survive on living or dead leaves and in the lawn thatch, forming a reservoir of inoculum. During the winter, they survive as mycelium within the thatch. In spring, favorable conditions trigger spore production and release.
Wind plays a crucial role in the dispersal of spores, carrying them to new areas of the lawn. When spores land on susceptible grass blades and encounter favorable moisture conditions, they germinate, initiating a new cycle of infection.
What are the Symptoms of Lawn Rust? Initial symptoms of lawn rust often include a gradual yellowing of the leaves, which can be mistaken for nutrient deficiencies. As the disease progresses, small, yellow-orange pustules (spore-producing structures) appear on the leaf blades. These pustules give the lawn a characteristic rusty appearance. In severe cases, affected leaves may dry out and die, resulting in brown patches and thinning of the turf.
Impact on Green Spaces, Sports Fields, and Golf Courses In environments where the visual and functional quality of the lawn is paramount, such as sports fields and golf courses, rust poses a significant threat. Beyond aesthetic concerns, the disease weakens the grass, reducing its resilience to wear and tear from foot traffic and other stresses. This can lead to bare patches, impacting playability and requiring costly maintenance interventions.
Prevention and Control
To effectively manage lawn rust, a combination of preventive and control measures is essential:
Proper Fertilization: Maintain a balanced fertilization program to ensure healthy turf growth and enhance disease resistance. Avoid excessive nitrogen application, which can increase susceptibility to some diseases.
Regular Mowing: Mow the lawn at the recommended height for the specific grass type. This helps to reduce thatch buildup and improve air circulation, which can help to dry the turf more quickly.
Proper Irrigation: Water deeply and infrequently, allowing the soil to dry out between waterings. Avoid overhead watering, which can prolong leaf wetness and favor disease development.
Shade Management: Prune trees and shrubs to increase sunlight penetration and improve air circulation within the lawn.
Thatch Control: Regularly dethatch the lawn to remove excessive thatch buildup, which can harbor disease pathogens.
Cultural Practices: Avoid excessive traffic on wet lawns, as this can damage the turf and increase its susceptibility to disease.
Roots and Soils Solutions for Lawn Rust Control:
At Roots and Soils, we provide natural products and biocontrol solutions for lawns in green spaces, communities, sports fields, and golf courses. If you need expert advice on managing lawn rust, please consult with us.
For soil improvement (aeration, decompaction, avoids felting):
GaiaOxy, GaiaSulfur
Our products against turf diseases (red thread, dollar spot, anthracnose, pythium, rust, etc.):
GaiaGard
Our biostimulants for your lawns (act as the first line of defence against diseases and pests):
GaiaVirox, GaiaShield and GaiaBoost
Request our protocol against the Turf Rust !
Red Thread Disease (Laetisaria fuciformis) is a common condition affecting lawns. It affects both residential lawns and sports fields such as golf courses, where it mainly occurs between spring and autumn. While its visual appearance may be alarming, it generally does not 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.
Table of Contents
Identity card of red thread of the lawn
Biological factors and propagation
What are the symptoms of red thread of the lawn?
Diagnosis and observation
Cultural methods of prevention against red thread
Agrobiotop solutions against red thread disease of the lawn
Identity card of red thread of the lawn
Red thread disease belongs to cryptogamic diseases and occurs mainly on grasses, plants widely used for lawns. Two fungi are responsible: Laetisaria fuciformis and Limonomyces roseipellis. These pathogens find a favorable ground 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 promote its rapid spread. Several elements influence its appearance:
Excessive moisture: the presence of dew, fog or night watering promotes the maintenance of a humid environment conducive to sporulation and spore germination.
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 established or developing lawns are particularly susceptible to this disease.
Nitrogen deficiencies: a lack of nutrition weakens plants, and nitrogen plays a key role in strengthening grasses against diseases.
Accumulation of felt: a thick layer of undecomposed organic matter prevents the roots from receiving enough water, air and nutrients, making the lawn more vulnerable.
What are the symptoms of red thread of the lawn?
The red thread of the lawn is manifested by diffuse spots that gradually spread. These yellowish or brown areas widen and take on a characteristic pink or red hue, especially in wet periods. Upon examination, red filaments or clumps of mycelium can be observed on the affected grass blades. The leaves begin to discolor by the tips, before drying out.
Although spectacular, this disease has only an aesthetic impact and does not affect the survival of the lawn. The plants temporarily stop their growth in the infected areas, but they can recover if conditions become favorable again. In spite of everything, if nothing is done, these lesions compromise the uniform appearance of the lawn and make it vulnerable to other stresses.
Diagnosis and observation
To identify this disease, regular observation of the lawn is necessary, especially between March and November, 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 confirms the presence of red filaments or mycelial structures. The areas to be monitored as a priority are those where the lawn seems less dense or where water tends to stagnate after watering.
Cultural methods of prevention against red thread
A suitable preventive approach can considerably reduce the risk of red thread appearance and maintain a vigorous lawn. Here are the actions to favor:
Management of nutrient intake: apply balanced fertilizers to avoid deficiencies, while ensuring a sufficient supply of nitrogen.
Diversity of seeds: sowing a mixture of varied grasses limits the risks associated with monocultures, which are often more susceptible to diseases.
Reduction of felt: regularly scarifying in spring and autumn improves the circulation of water, air and nutrients while limiting the accumulation of organic matter.
Aeration of the soil: coring is an effective practice to stimulate rooting and optimize the health of the lawn.
Watering management: prefer a morning watering to limit prolonged moisture during the night, while adopting spaced but abundant watering to strengthen the roots.
Hygiene of equipment: carefully cleaning the mowing tools after use avoids the spread of spores on other areas.
Mowing practices: maintain a cutting height of 5 to 10 cm and limit the frequency of mowing to reduce stress on plants.
Helminthosporiosis: a fungal disease
Have you noticed brown or gray spots on your lawn, followed by a rapid decline in certain areas? This may be helminthosporiosis, a fungal disease dreaded by lawn managers, sports field managers and garden professionals. This pathology, which mainly targets grasses, spreads rapidly under certain favorable conditions. What are its symptoms? How to fight with adapted solutions?
Table of Contents
Helminthosporiosis: a fungal disease
What are the symptoms of helminthosporiosis of the lawn?
Biological cycle and dissemination
How to prevent helminthosporiosis?
Agrobiotop solutions against helminthosporiosis of the lawn
Helminthosporiosis: a fungal disease
Helminthosporiosis is a pathology of fungal origin caused by fungi of the genus Dreschlera and Bipolaris. Several species, including Helminthosporium dictyoides, Helminthosporium siccans and Bipolaris sorokiniana, are responsible for this disease. These fungi mainly attack grasses used in lawns, such as Kentucky bluegrass, perennial ryegrass and fescues, leading to a significant weakening of lawns.
The disease is particularly active between spring and autumn, periods when climatic conditions favor its development:
High and persistent humidity, often caused by abundant dews, frequent rains or excessive irrigation.
Mild temperatures, ideal for the germination and proliferation of fungi.
Lawns already weakened by unsuitable practices, such as excess nitrogen, poor aeration or too short mowing, are more exposed. In addition, the presence of felt on the ground or excessive shade creates an environment conducive to infection. This context underlines the importance of balanced management to limit the risks and contain the impact of this disease.
What are the symptoms of helminthosporiosis of the lawn?
The first signs of helminthosporiosis appear as brown or gray spots that dot the leaves of lawns. As the infection progresses, these discolored areas extend, causing a visible decline of grasses. In the absence of intervention, the damaged patches can multiply rapidly and create bare spaces within the lawn.
Affected lawns often have a non-homogeneous texture and color, and their general appearance becomes dull. These symptoms, although attributable to various causes, are accentuated when climatic conditions remain favorable to the disease.
Biological cycle and dissemination
Helminthosporiosis fungi persist as conidia or dormant mycelium on plant debris left on the ground, such as uncollected mowing waste.
Dissemination is mainly by wind or by direct contact between infected and healthy leaves.
In addition, the presence of felt on the lawn creates an environment where fungi can easily move from one plant to another. This mode of propagation, associated with inadequate maintenance practices, accelerates infestation and complicates the management of the disease.
How to prevent helminthosporiosis?
The prevention of helminthosporiosis is based above all on rigorous and thoughtful management of the lawn. A balanced fertilization, favoring slow-release fertilizers, avoids excess nitrogen which weakens grasses.
Mowing should be carried out regularly, with a cutting height of about 50 mm, and the waste must be carefully collected to limit the spread of fungi.
Watering, a key factor in moisture management, requires special attention. It is advisable to avoid watering at night to reduce the duration of moisture on the foliage.
In parallel, soil aeration helps to improve air circulation and limit the conditions conducive to fungal development.