Introduction
Probably, the most plagued plant is the rose. Diseases, insects, and nutritional problems seem to plague the rose. The rose family includes a few trees: the crab apple, flowering pears, mountain ash, hawthorns, service berries, cherries, and peaches. The variety of roses includes vines, trees, bushes, and the ground cover type. Some roses are real roses but carry the name because of the shape the flower takes as it blooms. Following are the disease and problems of the rose.
History
The French Rose (Rosa gallica) and the Cabbage Rose (Rosa centifolia LINN.) were traditionally used as food and as an herbal remedy. The pedals were candied or used in tea. Baths filled with dried rose petals were used religiously by the Greeks. The rose hips, seeds found in the small pods that form under the pedals of the rose, contain more vitamin C than oranges.
The pedals of the rose trees, R. damascena and R. centifolia are used in perfumes and other scented products. The first rose perfume was created in 1612 after a bridal couple noticed how the rose oil collected on the water as the petals floated around the small row boat.
The R. gallica (a dark red rose) is grown for the medicinal qualities. The R. gallica and R. centifolia contain many hybrid varieties. The R. gallica and R. centifolia are the only types of rose that should be used as confection or medicinally. The R. gallica was known for the deep, velvety red color in the pedals.
The five wild varieties of roses are Dog rose (R. canina), Field rose (R. arvensis), Sweet Briar (R. rubiginosa), Burnet rose (R. spinosissima), and Downy rose (R. villosa). These roses are traditionally found in different areas in England. Each one has its own unique qualities.
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The French Rose (Rosa gallica) and the Cabbage Rose (Rosa centifolia LINN.) were traditionally used as food and as an herbal remedy. The pedals were candied or used in tea. Baths filled with dried rose petals were used religiously by the Greeks. The rose hips, seeds found in the small pods that form under the pedals of the rose, contain more vitamin C than oranges.
The pedals of the rose trees, R. damascena and R. centifolia are used in perfumes and other scented products. The first rose perfume was created in 1612 after a bridal couple noticed how the rose oil collected on the water as the petals floated around the small row boat.
The R. gallica (a dark red rose) is grown for the medicinal qualities. The R. gallica and R. centifolia contain many hybrid varieties. The R. gallica and R. centifolia are the only types of rose that should be used as confection or medicinally. The R. gallica was known for the deep, velvety red color in the pedals.
The five wild varieties of roses are Dog rose (R. canina), Field rose (R. arvensis), Sweet Briar (R. rubiginosa), Burnet rose (R. spinosissima), and Downy rose (R. villosa). These roses are traditionally found in different areas in England. Each one has its own unique qualities.
Diseases
The diseases plaguing roses are primarily fungal, attacking the leaves and occasionally stems and blooms. Fungal diseases thrive in the moisture found in the air and ground water. Spraying your roses with water on early Spring mornings may cause any one of these diseases, though the blackspot fungus prefers a hotter and humid climate.
Blackspot is a fungus that forms on the leaves. It begins with small black dots with a yellow halo surrounding them, spreading out to cover the entire leaf. The blackspot fungus is common in high humid and rainy areas. Powdery mildew covers the leaves in a fine powder and the leaves curl or twist. The powder can spread to the bulbs and stems. The powdery mildew is carried on the wind during cool, humid times. Spot anthracnose is spread through water and occurs in the early, cooler Spring weather. Small brown, red or purple spots form on the top of the leaves. When the center of these spots dries it turns white and may fall from the leaf. Botrytis blight attacks the rosebuds and covering them in a grayish brown fuzz of fungus and will not open. The blooms that are open contain flecks of brown, or yellow, some petals are wilted and brown. Botrytis blight is common on roses that are mailed in tightly sealed boxes. Canker is determined by the brown or red spots on the cane. The spots may crack and spread to cover the cane. Rust is a orange fuzzy fungus that develops on the bottom of leaves. Downy mildew are angular black patches found on the tops of leaves.
Crown gall is a bacterial soil born disease. The bacteria enter through the roots, wounds in the base of the plant at the roots and form small green balls along the bottom. Galls turn brown with age and cause stunting of your rose shrub. This rose disease robs your rose of nutrients stunting and starving it. Mosaic is a virus that forms in a netting style, leaves show mottling and yellowing. The rose buds are stunted if they grow at all.
Resources
Treatment Options
To treat fungal infections trim the infected leaves and stem. Treat infected roses with a fungicide. Follow the instructions explicitly. Do not compost your infected rose bushes. The fungus will contaminate your compost. Dispose of the shrub and pieces by placing them in a plastic bag and putting them in the trash.
There is no cure or treatment for Crown gall or Mosaic rose diseases. If your plant is badly infected remove the plant. If your plant is infected with gall the soil surrounding the plant must be removed. Another suggestion is to cut the galls with a sharp knife or shears and disinfect your tools in rubbing alcohol or bleach.
Resources
Ohio State University Extension Fact Sheet: Controlling Rose Diseases
