Roses can be a stunning addition to your backyard landscape, lending lush green foliage and sweet-smelling blossoms to your garden. Though roses are relatively hardy, they may occasionally fall victim to problems. Troubleshoot your rose bush or vine for some of the most common issues that affect roses, including mineral deficiencies and insect invasions.
Poor growth and little to no flowering are common signs your rose bush or vine is not getting enough sunlight. Most rose species need at least five hours of sunlight per day for proper growth. You may need to trim surrounding plants or trees, or transplant the bush, to resolve this problem.
Yellow to yellow-green or white foliage may mean your roses are suffering from a trace element or mineral deficiency. Fertilize the rose bush regularly with a compound rose-specific fertilizer containing magnesium, potassium and iron. Regular watering also is critical. Confirm that you have watered sufficiently by checking the moisture levels three to four inches below the surface of the soil. This area should be consistently moist for proper rose growth.
Several types of insects can attack your rose bush, sucking its sap, eating its foliage and weakening the plant. If not treated immediately, the bug population can swell, overwhelming the bush and killing it. Common pests include Rose Chafers, Rose Bud Borers or leaf bettles, and Japanese Beetles. Make a homemade insecticide by mixing 1 qt. of water with 3 tbsp. of liquid dish soap. Spray the solution on your rose bush, killing the insects and deterring future invasions by coating your roses with a soapy film. If this doesn't control the insect population, resort to more toxic insecticides based on pyrethrum or pyrethrin, available at nurseries and garden stores.
Powdery mildew is a very common rose problem in areas with high humidity. Symptoms typically center on a thin, powdery residue that coats all of the rose plant's leaves. Minimize your chances of encountering powdery mildew on your roses by increasing air circulation around your bushes and not watering in the evening. Treat the growths with a commercial product containing sulfur.
Fungal diseases, like cankers and black spots, can form on your roses. If left untreated, they can kill your plant's foliage and stunt new growth and flowers. Treat these diseases with sulfur- or copper-based fungicides.