Lawns and plants with fungus need F-Stop Lawn & Garden Fungicide from ferti-lome. Use F-Stop on roses, flowers, shrubs, berries, fruits, nuts, vegetables, and lawns. It's most effective when it's used to prevent fungus, so begin application early in the season if conditions are cloudy and rainy or where disease has been present in prior years. F-Stop controls common fungus such as powdery mildew, black spot, rust, blights, scab, leaf spot, brown patch, and others. Do not apply when temperatures are higher than 90 degrees. 16 oz. concentrate bottle.