Black Spot on Roses
Nothing is as lovely as a rose. Except when it gets black spot. And once your plant succumbs to this disease you are most likely destined to battle it every season.
Avoid the problem by growing resistant roses. I only grow hardy shrub roses in my garden. No winter protection or pesticides needed for these beauties.
If you do have black spot susceptible plants remove the leaves on the bottom 6 to 12 inches of the stem early in the season. This reduces the fungal spores splashing from the soil, onto the leaves and infecting the plants.
Always remove and destroy infected leaves especially in the fall. Proper spring pruning can also help reduce potential sources of this disease.
If your garden becomes infected and the plants are susceptible you may choose to spray. Start with one of the more eco-friendly products like fungicidal soap, Neem, sulfur and baking soda. Spray every 7 to 10 days throughout the season.
A bit more information: You may be surprised to find a wide selection of roses that are resistant or at least tolerant of black spot. The Knock out series of roses has become a favorite due to their long blooming disease resistant character.
Mary Ann Hansen, Extension Plant Pathologist, Department of Plant Pathology, Physiology and Weed Science, Virginia Tech put together this list of some of the roses with good to excellent resistance to black spot and powdery mildew.
- Hybrid Teas: Canadian White Star, Chablis, Duet, Electron, Elmhurst Lady, Lady Rose, Lady X, Maid of Honor, Mikado, Miss All American Beauty, Modern Art, Mon Cheri, Nantucket, Olympiad, Otto Miller, Pascale, Polarstern, Red Devil, Voo Doo, Wimi
- Grandifloras: Love, Prima Donna
- Floribundas: Koricole, Lavaglut, Playboy, Playgirl, Simplicity, Sun Flare, Traumerei
- Miniatures: Always A Lady, Anytime, Black Jade, Centerpiece, Cinderella, Cuddles, Ginny, Green Ice, Heartland, Kathy Robinson, Mary Bell, Old Glory, Queen City, Red Flush, Singles,
- Shrub Roses: Alba Meidiland, Albo Semi-plena, Blanc Double de Coubert, Bonica, Frau Dagmar Hartopp, Linda Campbell, Pink Meidiland, Roseraie de l'Hay, Rugosa alba, Scarlet Meidiland, Topaz Jewel