When the morning dew is still on the lawn, you’ll notice spots of grass that look like cotton candy or like a white spider web in a localized area. That web-like, cottony stuff you’re seeing is actually the fungus, called mycelium. Dollar spot can also look like straw-colored spots (the size of a silver dollar).
Spots found in lawns that are brown with a reddish-pink tinge may be red thread disease. Red thread is generally an indication of low nitrogen levels in lawns. It is found when temperatures are between 50°-75° and humidity is high. When red thread attacks a lawn it is time to fertilize. More than likely this disease will not kill a lawn but it will make the lawn look bad. Irregular shaped patches of red thread can reach up to twenty-four inches in diameter.
The causal fungi usually first invade the leaves, producing small brown spots. As the disease worsens, the spots on leaf blades expand and produce a dark purplish-red oval border around a tan center. The spots enlarge until the entire width of the leaf blade is blighted. The leaf-spotting or leaf-blighting phase is less damaging to the turf grass than is the melting-out (crown and root-rot) phase of the diseases. In melting-out, the crowns and roots are damaged, causing severe thinning of the turf.
Green Side Up offers a preventative AND post application Disease Control Program to handle your lawn’s fungicide needs to help aid in lawn disease control. We look to provide you with the most personalized information pertaining to your lawn possible during each visit to your property. If any of our technicians notice this disease (fungus) activity on your lawn, we will be sure to make your aware of its presence, and any actions that need to be taken to resolve this issue, or any others.
What Causes Lawn Disease
Lawn disease in turf grasses, as in other plants, develops from an interaction among a susceptible plant, a disease-producing organism (pathogen), and an environment favorable for disease development. Susceptible grasses and pathogens (usually fungi) are present in all lawns. In most cases, the pathogens exist in a dormant or saprophytic (feeding on dead or decaying substances) state and do not attack living plants. Diseases occur when environmental conditions (weather, management, and/or site conditions) become favorable for the build up of pathogen populations and/or cause an increase in the susceptibility of the plant. When this happens, turf grass loss can occur. It is crucial that treatments be applied to prevent further damage.
There are a group of turf grass diseases for nearly every environmental condition that may arise. Some diseases develop during the frigid months of winter under a blanket of snow, whereas others occur only during the hottest and most humid conditions of summer. Some diseases appear more frequently in wet soils and following applications of high rates of fertilizer, while others are triggered by drought and low fertility.
Brown patch appears as circular patches, ranging from a few inches to several feet in diameter. The infected leaves first appear water soaked and dark, eventually drying, withering, and turning dark brown. A dark smoke ring often surrounds the outer margins of the diseased area when humidity is high and disease is actively growing. Leaves in the blighted area are usually killed, and the disease can rapidly kill large areas of turfgrass in short periods of time under conducive conditions.
The symptoms of summer patch appear in circular patches or rings, ranging from 6 inches to 3 feet in diameter. Turf within these patches is initially off-colored, prone to wilt, growing poorly, or sunken in the turf stand. Over a period of one to two weeks, the turf continues to decline, turning yellow or straw brown and eventually collapsing to the soil surface. The outer edges of the patch are usually orange or bronze when the disease is actively developing. Affected plants are easily pulled up from the turf, and visual examination reveals that the roots, crowns, and rhizomes are black and rotten. The patches recur in the same spot annually, and expand at a rate of 2 to 4 inches per year. Resistant grasses, such as creeping bentgrass, fescues, or weedy species, are often present in areas damaged by summer patch.
Mushroom appearance often causes people to be concerned about the health of their lawn and whether or not a serious disease might be getting started. It’s important to remember that mushrooms are the ‘fruiting bodies’ of fungi living in the soil and thatch. They are responsible for the production of microscopic spores that in turn help propagate the fungus. The vast majority of those fungi are not associated with any lawn disease causing organisms. It’s quite common for them to appear during periods of moist conditions resulting from either natural rainfall or excessive irrigation. The fungi are living on decaying organic matter in the soil and/or thatch layers. If you find the mushrooms offensive, simply knock them over with a rake and remove them from the area.