In a previous blog I shared a story about my grandfather’s award-winning roses. I also shared memories of the countless days I spent helping him cultivate his prize-winning specimens. He poured so much time and energy into creating those spectacular rose gardens, but his efforts went beyond physically tending to the fragrant flowers. He also spent hours sitting on his recliner reading books about roses. His research helped him create the right environment to maximize growth and it also taught him how to identify and combat a rose bush’s many “enemies.”
One of the most common and problematic diseases facing any one who grows roses is a fungus called Black Spot. It first appears as a scattering of black spots across the rose leaf, but soon more lesions appear, the leaf yellows, and ultimately it drops from the plant. Lower leaves become infected first, but the disease often moves up the plant and attacks it until the entire rose bush has been defoliated.
Wind, rain, and humid conditions exasperate the fungus, which can easily spread to new leaves. Without treatment it creates a cycle that can continue from season to season.
To lessen the spread of Black Spot in your rose garden follow these simple tips:
· Make sure roses are exposed to full sunlight and are spaced far enough apart to encourage airflow and speed drying of your plants.
· Water your roses in the morning and early afternoon and try to keep all water off the foliage.
· Remove dead leaves and other rose debris from the garden area.
· Select varieties that are highly resistance to black spot, including Carefree Delight, Blanc Double De Coubert, Fru Dagmar Hastrup, Henry Kelsey and William Baffin.
Finally, if all else fails, consider applying a product such as Bayer’s Disease Control for Roses, Flowers and Shrubs.