Rose-bush-problems, the black spot fungus, if left untreated, can totally defoliate a rose bush, causing a weakening of the overall rose bush, thus high stress on the plant. this particular disease is a worldwide problem for rosarians and gardeners that grow roses.. Yellow mottling on rose leaves is the first sign of mosaic virus, followed by dropped leaves and dead plants. a mild infection of mosaic may not cause any lasting problems, but severe infections can destroy a rose bush. creative commons/ malcom manners mosaic virus prevention and treatment, roses have a reputation for being prone to problems. sometimes this reputation is well-deserved, as anyone who has grown an older variety of rose has most likely had to deal with black spots on an annual basis. that's starting to change, as many modern roses are bred to be disease-resistant and low-maintenance..
Problems of bush roses first those fungal diseases white, black or rusty spots on leaves are from fungal diseases. black spot, powdery mildew, and rust are the three major disease problems of roses., rose problem 2 - distorted and stunted plants this is another common rose disease, this one known as powdery mildew. this is a fungal disease, and it coats the stems, foliage, and buds with what appears to be a white powder. this coverage in turn causes the leaves to turn purple and appear unsightly..
Rose rosette disease, also known as witches'-broom of rose, is a virus or virus-like disease, that is spread by a microscopic eriophyid mite. the main symptom is a tightly grouped, proliferation of distorted, usually bright red foliage (a witches'-broom). affected canes may be excessively thorny, thicker than unaffected canes and slow to mature., aphids and spider mites are two of the biggest pest problems faced by rose gardeners. both are small insects that congregate on the leaves of rose bushes and other garden plants. the simplest cure....
Rose rust is a disease caused by the fungi phragmidium species. it causes orange-colored spots to appear on stems and leaves. when rust is severe, an orange dust-like substance may be present on the plant surface and on the ground below the plant. rose rust attacks all plant parts except the roots and petals.