Treating Diseased Rose Plants
Here are a few basic tips for maintaining rose health and vitality. The first step in treating diseased rose plants is to identify the cause. Find your specific symptom below:
Leaves with small black spots
Black spot is a common disease that harms rose leaves. The spot show up in a circular pattern and might cause damage to the edge of rose leaves. Leaves that show this symptom often turn slightly yellow in color. Quickly remove any diseased leaves. Ensure that the plants do not get too much water on the leaves. You might want to consider a foliar application of rose fertilizer to help provide nutrients needed to overcome the problem.
Young Canes that are stunted or malformed
This symptom is likely caused by a fungal disease called powdery mildew. This fungus attacks leaves, buds, and stems. This white powder will cause your rose leaves to appear purple. Treat with a fungicide to prevent the spread of powdery mildew. Also keep in mind that healthy plants are better able to resist disease.
This problem often causes orange or red blisters to form in the warm months. The diseased leaves will turn black in autumn. Be extra cautious because rust can survive through winter. Roses tend to be more disease resistant if they have all the nutrients they need. Consider applying Liquid Organic Bonemeal to the leaves to help prevent rust.
Stunted or misshapen leaves and flowers
This can often be a sign of spider mites. Look on the underside of your leaves for small red, yellow, or green spiders. A foliar application of AGGRAND Kelp and Sulfate of Potash might be helpful, but you should also look for a natural pesticide to treat the infestation.
Small white webs under leaves
Often a sign of aphid infestation, this problem can weaken rose leaves. Aphids feed on juices from the tender buds and new leaves. Ladybugs are a natural predator. Consider setting up a ladybug habitat to help limit aphid populations.