Diplocarpon rosae, or black spot fungus does not just affect roses. This fungus can affect any plant in your garden that has fleshy leaves or stems. Identifying this fungus should be easy enough, since the name accurately describes the first stage of infection. Plants with this disease have black spots, and when it progresses, the leaf around the spot starts to turn yellow, until eventually the entire leaf is yellow and falls off. On the plus side black spot fungus does not kill plants, but it is very unsightly. This fungus grows in the spring when temperatures start to climb into the sixties, and does not stop until temperatures reach the mid eighties. This fungus also thrives when plants are wet for 6 to 9 hours in the day.
With the weather heating up, grass is going to struggle to stay green. Make the choice to either commit to watering and keeping it green or letting it go dormant and brown. If you let your grass go dormant and then decide to water it, you could be harming your lawn. Breaking dormancy cycles costs the grass a lot of food and energy reserves, and makes it more susceptible to disease. If you commit to watering and keeping up with it, you can let your lawn go into a mild drought. If you walk on your lawn and you can see the footprints left behind, that is a sign of mild drought. This is beneficial to the grass because it stimulates root growth.
While fungus naturally occurs in grass and can be harmless, certain conditions can cause these fungi to become harmful diseases to your grass. Weather conditions, especially temperature and humidity, can make certain fungi flare up, and too much rain or drought can also cause disease. Mowing too low of a setting and cutting the grass off closer to the roots can make it more susceptible to fungus, and large amounts of fertilizer can green up your lawn quickly, but too much nitrogen can lower grass’ defense against disease. Here are some tips to help prevent disease in your lawn: