I have oval,tanish spots on my iris. They appear every year about the same time as blackspot on roses. I have sprayed the soil and the iris foliage but can't seem to stop it. |
Iris sometimes get a bacterial leaf spot, a fungal leaf spot, rust, or an infestation of thrips insects. It's difficult to pinpoint the problem without seeing it firsthand. If you can provide full sunshine and good air circulation around the plants, you can avoid the fungal and bacterial problems. Thrips are tiny insects that jump from leaf to leaf, and are harder to control. Try to monitor your iris - as soon as you see a brown area developing on a leaf, remove that leaf to keep the problem from spreading to other leaves. At the end of the season, after the plants have finished blooming, the leaves naturally wilt and die. Remove the dead leaves and keep the iris bed clear of all whithered leaves throughout the winter. If your iris are overcrowded, dig and divide them in late summer. Hope this information helps! |