Rose Leaf Damage

Louisiana’s warm, humid weather encourages the development of several serious diseases that can damage rose bushes. Based on the picture, it appears as though there may be more than one problem occurring on your rose. The white powdery appearing substance appears to be Powdery Mildew. You may also have black spot. The darkened areas covering the center of the leaves could be another disease process. First, timely treatment is critical, especially since multiple issues may be present. To simplify treatment, we recommend that you can take several leaf samples showing the variations of problems to a nursery for a definite diagnosis and treatment options. Also, here’s a link to the Louisiana Extension Agency with more information on rose diseases and treatments for your area – http://www.lsuagcenter.com/NR/rdonlyres/FAB0070C-C6BA-405F-A150-D4086F0064C1/38087/pub2613rosediseasesHIGHRES1.pdf

Because roses in your area are susceptible to many diseases, the best cure is actually prevention. You may already be aware of some of the rose basics such as using mulch, planting where there’s good drainage, avoiding overhead watering, and making sure roses get 6 or more hours of direct sunlight daily. Here’s a link for general rose care for your area that may be helpful in preventing future problems – http://www.lsuagcenter.com/NR/rdonlyres/FAB0070C-C6BA-405F-A150-D4086F0064C1/38087/pub2613rosediseasesHIGHRES1.pdf