Bulbs
Flower Basics
Flower Beds & Specialty Gardens
Flower Garden
Garden Furniture
Garden Gnomes
Garden Seeds
Garden Sheds
Garden Statues
Garden Tools & Supplies
Gardening Basics
Green & Organic
Groundcovers & Vines
Growing Annuals
Growing Basil
Growing Beans
Growing Berries
Growing Blueberries
Growing Cactus
Growing Corn
Growing Cotton
Growing Edibles
Growing Flowers
Growing Garlic
Growing Grapes
Growing Grass
Growing Herbs
Growing Jasmine
Growing Mint
Growing Mushrooms
Orchids
Growing Peanuts
Growing Perennials
Growing Plants
Growing Rosemary
Growing Roses
Growing Strawberries
Growing Sunflowers
Growing Thyme
Growing Tomatoes
Growing Tulips
Growing Vegetables
Herb Basics
Herb Garden
Indoor Growing
Landscaping Basics
Landscaping Patios
Landscaping Plants
Landscaping Shrubs
Landscaping Trees
Landscaping Walks & Pathways
Lawn Basics
Lawn Maintenance
Lawn Mowers
Lawn Ornaments
Lawn Planting
Lawn Tools
Outdoor Growing
Overall Landscape Planning
Pests, Weeds & Problems
Plant Basics
Rock Garden
Rose Garden
Shrubs
Soil
Specialty Gardens
Trees
Vegetable Garden
Yard Maintenance
Why Does the Stem of the Rose Bush Get White Substance?
Why Does the Stem of the Rose Bush Get White Substance?. Infected rose bushes have the potential to destroy your entire rose garden if you're not careful. There are several types of disease that cause a white substance on the stem of the rose bush. Both powdery mildew and brown canker cause white, powdery lesions on the stem. Fortunately, neither...
Infected rose bushes have the potential to destroy your entire rose garden if you're not careful. There are several types of disease that cause a white substance on the stem of the rose bush. Both powdery mildew and brown canker cause white, powdery lesions on the stem. Fortunately, neither of these conditions cause the death of the rose bush if you catch them early.
Powdery Mildew
Powdery mildew causes a white substance to form on leaves and rose canes. This disease starts as a blistered surface on young leaves caused by the fungus Sphaerotheca pannosa that spreads on the wind. Unfortunately, powdery mildew is found in most growing zones, so the chance being downwind of an infected plant is fairly large. You'll need to monitor your roses carefully; treatments applied when early symptoms appear are simpler, less invasive and far more effective than later-stage treatments.
Brown Canker
Another disease that causes a white substance to appear on the stems and leaves of roses is brown canker. While the name suggests a brown canker appearing, this disease manifests as a gray-white lesion on the stem's surface. These lesions spread over the stem and onto the leaves, then once the plant is fully infected, the lesions become brown to give the disease its distinctive name. Brown canker can kill the entire rose plant so treatment when symptoms first appear is critical.
Disease Control
To save the life of your rose bush, start treatment when symptoms first appear. When symptoms of powdery mildew first appear it can be washed or gently sprayed off using a garden hose. Once the disease has taken hold, commercial fungicides can be applied to control damages. Brown canker can only be controlled by removing diseased rose canes. When cutting canes infected with brown canker, the shears need to be disinfected in 10 percent diluted bleach between each cut to avoid spreading the disease.
Preventing
Preventing rose diseases involves proper maintenance of the plant throughout the growing season. Planting roses further apart promotes good air flow, as does appropriate pruning. Removing any sick or diseased parts of the plant as soon as symptoms appear prevents the spread of disease to healthy parts of the plant. Finally, treating plants with a commercial fungicide prevents the spread of a disease from infected plants.
