Despite many efforts to keep roses disease free, there are some diseases that can affect rose plants. Identify the common rose diseases to produce quality roses in your garden.

4 Common Rose Diseases and tips to control them:

1. Black spot: It is a fungal disease that produces round black spots with fringed edges on leaves. It is common in moist weather as it is water borne disease. On some rose varieties, yellowing may occur on the leaves. Infected leaves will fall off, making the plant almost defoliated. Such plants become weakened and die over in winter season.

Control: Select and plant the varieties that are black spot resistant. To avoid foliage, do not splash water on the leaves. Plant the rose in sunny areas and water the plant in the morning so that if water falls on the leaves, it will quickly dry off. When new leaves start to appear in early spring, start to use fungicidal sprays.

2. Powdery Mildew: It is a fungal disease that covers leaves, buds, flowers, and stems with white powder. The disease can cause new leaves to curl and become purple. It mostly appears on warm, dry days followed by cool, moist nights. This disease is also spread to older leaves. The leaves appear normal on the upper surface in spite of excessive fungus growth on the bottom side of leaf.

Control: Choose fungus resistant varieties while planting new rose plants. Plant the roses in sunny areas to prevent mildew development. During the growth season of roses, prune the surrounding shrubs to allow more air to the rose plants and remove all diseased leaves.

3. Mosaic virus: It is a viral disease that causes bright yellow mottling on leaves. Some of the rose varieties become stunted with this virus. There is no cure for the infected plants.

Control: You can choose virus resistant roses. Once you prune the infected plants affected with this virus, do not use the same pruners to prune healthy plants. Dip the pruners in a ten percent solution of chlorine bleach in water to disinfect them. When the plants are severely infected, remove and destroy them.  

4. Stem or cane cankers: Several fungi produces stem cankers on rose plants. The stem cankers are normally brown, sunken, oval shaped or withered areas that appear everywhere on the cane. As soon as the canker destroys the cane, the cane dies off. The leaves wither from the canker. You can see fungus spore with small black specks on the cane within the cankered spot.

Control: Choose the varieties that are rose disease resistant. Prune the diseased canes and destroy them. Take care of the plants from cold weather with mulch. Fertilize and water the plants properly.

Image via Wikipedia