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There are several diseases that can cause problems for lawns in our area. But first, it is important to understand how diseases develop. An interaction occurs among a susceptible host plant, the pathogen or disease-producing organism and environmental conditions which favor a particular disease development. Since susceptible grasses and pathogens are present in most lawns, it only requires that environmental conditions (usually weather) are favorable for a certain disease or fungus to become active. When these environmental conditions change, it usually will break this interaction and the symptoms of the disease will disappear. The adage that proper lawn maintenance reduces lawn problems is especially true concerning lawn disease. Proper mowing, watering, fertilization and thatch management all play important roles in lawn disease prevention.

Fungicides are available for the prevention or control of lawn diseases. Keep in mind that fungicides are costly and may need to be reapplied to be effective. In most cases, they aren’t worth the investment because the most common lawn diseases in our area are more of a cosmetic problem than one that actually causes damage to turf grass. The following are just a few common diseases that we see in this area.

Snow Mold

Erie Snow Mold

This disease develops under snow or at the margins of a melting snow bank. It will also occasionally develop without snow being present where moist conditions exist through the winter months.

The most notable symptoms are white, gray or pinkish circular patches of matted down grass. A fungicide treatment just prior to the first snowfall is only recommended on lawns that are less than a year old or where snow mold has been an ongoing problem. However, it is important that homeowners lightly rake these areas in the spring. By breaking up the matted down layers on top, you allow air and the sunlight to encourage new growth and faster recovery. Perennial Rye, creeping bent grass, and tall fescue are the types of grass most susceptible to snow mold.

Red Thread

Red thread disease in erie

Pink Patch

Pink Patch

These two diseases present similar symptoms and appear as irregular shaped patches of blighted grass ranging in size from two inches to three feet in diameter. From a distance, effected areas will have a pinkish cast. Upon closer examination, red thread disease will display a bright thread-like pink mycelium at the tips of infected leaves. In the case of pink patch, effected leaves are covered with a pink fluffy growth.

Red thread and pink patch develop most rapidly when our temperatures are between 65 and 75 degrees with prolonged periods of rainy or humid weather. Pure stands of perennial rye grass or fine fescue are most susceptible to these diseases. A fungicide treatment would only be warranted in cases of extreme outbreak. In most situations, it disappears when the humidity drops or the temperature moves out of the ideal range.

Rust Diseases

Rust disease erie pa

There are a number of different rust diseases that affect turf grass, but they all generally occur under the same environmental conditions. Rust is normally a late summer or early fall disease occurring during prolonged periods of overcast weather. It will first appear as a light yellow flecking on the grass leaves. Next, these spots develop into reddish-brown pustules. An affected lawn will exhibit a rust colored cast that is noticeable from a distance. When walked upon, a red powder will collect on your shoes. In general, rust diseases do not injure turf grass and fungicide treatments are only used as a last resort. Adequate nitrogen and irrigation to maintain growth through late summer will minimize rust infections.

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