Lawn Diseases

The following is a short list of most commonly found disease and fungus in Edmonton and area, however this is not an exhaustive list of all disease and fungus that can develop on your lawn, If you have any questions or concerns about the potential presence of disease on your lawn area, feel free to further consult with your Maxigreen professional consultant.

Fairy Rings: Easily identified by circular or semi-circular area of darker grass on the inner and outer area surrounding the ring with dead grass forming the inner circle. In more severe and prolonged case of fairy ring growth, you may also notice the fungal growth within the ring.

There is no remedy or treatment for fairy ring outbreak. Aerating and fertilizing the area affected will fortify your lawn’s ability to naturally fight the outbreak. Managing the thatch thickness will also remove the chance of fairy ring outbreak as well as reduce and hinder the rapid growth and spread of the fungal outbreak. In more severe outbreak cases you may have to completely remove the soil in and around the ring (with at least one foot in each direction around the ring even if growth is not noticeable in those areas) and re-sod with fresh soil and seed. Whichever approach you choose to be careful of contact spread of the fungus to healthy areas from traces left on equipment (the mycelium will propagate and move to other areas of the lawn if the conditions are right).

Leaf Spot / Melting Out: Easily identified by purplish-red to purplish-brown borders and brown to tan centres on leaves and blades. Melting out begins at leaf level and will progress into crown and roots causing the rapid damage and degradation of your lawn’s health. The disease mainly develops where excessive thatch has built up or on areas where overfertilization (nitrogen in particular) has occurred. Excess shade, broadleaf herbicides of a certain kind or mowing your lawn to close, will contribute to the disease development. Proper watering, fertilization as well as thatch control will help lawn recover on its own in mild to moderate cases whereas fungicide application may be considered as a last resort in severe cases and outbreaks of leaf spot disease

Dollar Spot: Easily identified by the visual appearance of straw-coloured patches of dead grass with sometimes the faint appearance of cobweb-like coverage (especially in early mornings) on leaves and blades of affected plants. In early stages of development, the appearance of the spots may give more of the tan colored appearance with reddish-brown borders. Typically developing in high humidity and high thatch where moisture remains on the surface and cannot reach to the root area. Also prone are any lawn areas that are under stress from root damage (insects, cutting lawn to low or leaving grass growth high, not aerating the thatch etc.). By keeping your lawn maintained (fertilized, aerated and watered) the lawn should typically repair and recover from the disease on its own, however, in more severe cases, the application of the fungicide may be required to cull the growth and propagation of dollar spot disease within your lawn.

Brown Patch: Circular or crescent-shaped patches with a dark grey to dark purple ring appearance in early mornings. Prone areas of lawn are areas where high temperature and high humidity keep lawn wet for prolonged periods of time. To remediate and prevent growth, maintain thatch and drainage of problematic areas and apply proper amount as well as right kind of fertilizer (mediate the amount of free and available nitrogen that is the primary food for this fungus-based disease). In extreme cases and heavy outbreak, the application of fungicide may be required to fight the outbreak and spread of the brown patch disease.

Powdery Mildew: Easily identified by white powdery coating on leaves and blades with blades turning yellow-orange or brown at latest stages and more severe infestations of the powdery mildew. Most commonly developing in shady and wet areas of the lawn where severe moisture and lack of air circulation create the ideal growing condition for the powdery mildew growth. To prevent the outbreak of powdery mildew keep your lawn freshly mowed, mediate drainage and thatch buildup and consider seeding prone areas with grass types that are more tolerant to shade. Finally be mindful of how and what kind of fertilizer you apply to areas affected and avoid fertilizers with high nitrogen content that may aid in growth and propagation of powdery mildew.

Tip. Certain decorative plants such as petunias are prone to powdery mildew and may be severely affected by the outbreak. Certain vegetables such as cucumbers are also prone to the powdery mildew so please inspect and watch those for any signs of development.

Slime Mold: Easily identified by the development or appearance of the creamy-white slimy substance that is coating the leaf blade (with later stages the slimy coating turning powdery white, grey or blue-grey). The appearance of those patches on your lawn may be compared to spilt oil. Rather than unsightly appearance the mold is not damaging to your lawn and may be easily removed from the lawn by brushing it off.

Snow Mold: As the snow melts in the spring you may notice odd areas of dead grass covered with a grey, white or pink mold. To prevent the disease from developing on your lawn in spring do not over apply fertilizer to late in spring, rake and remove dead leaves and other debris before the snowfall. As the snow recedes in the spring, break off coverage of snow in areas where snow may stay longer (shade, underneath trees and shrubs etc.). In more severe cases of infestation, the application of fungicide may be considered however in most mild cases of the snow mold outbreak the simple remediation and prevention will do the trick by stopping the development of the disease in early spring when your lawn is most prone to it.