The Plant Doctor
Black Spot, Cercospora Leaf Spot, and Powdery Mildew of Roses
By Dr. Alan Henn, Extension Plant Pathologist.
MSU Extension Service publication P2827
Most plants require timely watering, fertilization, and pruning, but many roses also require good healthcare, as well. As head gardener, you are the primary physician for your roses. As physician, you must understand the cycle of diseases that can wreak havoc upon your garden friends. Periods of heavy dew, rainy weather, and high humidity favor the development of some major rose diseases: black spot, cercospora leaf spot, and powdery mildew. This means these diseases will almost always be present in the South, so you must keep ahead of them using preventive techniques.
Black spot, cercospora leaf spot, and powdery mildew
Most common during spring and fall when turf is emerging from or entering dormancy.
Weather
Leaf wetness periods of about 12 hours, but can be much less in high humidity; temperatures in the 50s to 90s for symptoms, but spore germination can occur as low as 32°F.
Plants affected
Black spot: All roses, but especially hybrid tea types.
Cercospora leaf spot: All roses.
Powdery mildew: Usually antique and climbing roses.
Quick symptoms
Black spot: Black or very dark brown, small (pencil lead-sized) spots to large spots as much as three-quarters of an inch in diameter. All spots will have a fuzzy margin, but you may need a hand lens to see it on small spots.
Cercospora leaf spot: Very circular spot, usually with smooth edges and a brown/purplish ring
surrounding a gray or light tan center.
Powdery mildew: White material on the surface of the leaves that may rub off. Young leaves may be distorted.
Download the Extension Publication P2827, above, for more information
Black Spot, Cercospora Leaf Spot, and Powdery Mildew of Roses
By Dr. Alan Henn, Extension Plant Pathologist.
MSU Extension Service publication P2827
Most plants require timely watering, fertilization, and pruning, but many roses also require good healthcare, as well. As head gardener, you are the primary physician for your roses. As physician, you must understand the cycle of diseases that can wreak havoc upon your garden friends. Periods of heavy dew, rainy weather, and high humidity favor the development of some major rose diseases: black spot, cercospora leaf spot, and powdery mildew. This means these diseases will almost always be present in the South, so you must keep ahead of them using preventive techniques.
Black spot, cercospora leaf spot, and powdery mildew
Most common during spring and fall when turf is emerging from or entering dormancy.
Weather
Leaf wetness periods of about 12 hours, but can be much less in high humidity; temperatures in the 50s to 90s for symptoms, but spore germination can occur as low as 32°F.
Plants affected
Black spot: All roses, but especially hybrid tea types.
Cercospora leaf spot: All roses.
Powdery mildew: Usually antique and climbing roses.
Quick symptoms
Black spot: Black or very dark brown, small (pencil lead-sized) spots to large spots as much as three-quarters of an inch in diameter. All spots will have a fuzzy margin, but you may need a hand lens to see it on small spots.
Cercospora leaf spot: Very circular spot, usually with smooth edges and a brown/purplish ring
surrounding a gray or light tan center.
Powdery mildew: White material on the surface of the leaves that may rub off. Young leaves may be distorted.
Download the Extension Publication P2827, above, for more information
|
Lee County Master Gardener Projects
The Lee County Master Gardeners lead and participate in many projects that help to promote gardening and serve as beautification to areas in Lee County. The projects provide a way to engage the public in gardening activities and to share current ideas and develop new ideas. Please use the Master Gardener Project button to explore and learn how the Lee County Master Gardeners contribute their time and love of gardening with the community. |
Mississippi Vegetable Gardener's Guide
MSU Extension Publication Number: P3616
View as PDF: P3616.pdf
Variety Recommendations for Mississippi Vegetable Gardens
MSU Extension Publication Number P3744
View as PDF: P3744.pdf
There are many good reasons for growing a vegetable garden in Mississippi.
MSU Extension Publication Number: P3616
View as PDF: P3616.pdf
Variety Recommendations for Mississippi Vegetable Gardens
MSU Extension Publication Number P3744
View as PDF: P3744.pdf
There are many good reasons for growing a vegetable garden in Mississippi.
- A garden offers the opportunity to enjoy vegetables at their freshest. Sometimes only minutes elapse between harvest, preparation, and eating. Most fresh vegetables available at the grocery store travel about 1,800 miles between producer and consumer, and this travel often occurs over a period of several days. There’s a lot to be said for “homegrown” freshness.
- In recent years many people are growing vegetables to save money on their grocery bill.
- A garden can be a wonderful place for children. They provide opportunities for play, learning, and for having fun.
|
Magnolia Botanical Gardens
Verona Research and Extension Center Magnolia Botanical Gardens serves as a demonstration and educational resource for green industry professionals and consumers. There are many ornamental plants in the botanical gardens including Mississippi Medallion plants. Many plants are labeled for identification. The public is invited to view these gardens to see plants they may want to include in their landscape. Magnolia Botanical Gardens is located at the Verona Research and Extension Center, south of Verona, MS on Hwy 145. |
Location:
MSU Lee County Extension Office
5338 Cliff Gookin Blvd.; Tupelo, MS 38801
MSU Lee County Extension Office
5338 Cliff Gookin Blvd.; Tupelo, MS 38801