The good news is the plants will survive. Powdery mildew is a common fungal disease on bee balms. That being said, the best strategy is always to choose plants that are resistant or at least tolerant to the disease. If mildew is a problem in your garden, consider growing this 3-foot-tall beauty with bright pink flowers. In 1993, the Chicago Botanic Garden evaluated the mildew resistance of 41 beebalm varieties over a 4 year period. Plants infected with powdery mildew often look like they have been dusted with flour. Other powdery mildew resistant bee balm varieties include ‘Marshall’s Delight’ (bright pink), ‘Jacob Cline’ (deep red), and ‘Raspberry Wine’ (dark red). It also has the darkest purple flowers of all of the monardas. Bee balm, or monarda, is a spectacular plant when grown under the right conditions. Examples of resistant species include 'Violet Queen,' 'Marshall's Delight,' 'Gardenview Scarlet' and 'Stone's Throw Pink,' according to studies conducted by the University of Vermont. Gorgeous and seemingly happy , healthy, and spreading more each year and then mid June comes the powdery mildew. And its lavender-pink flowers were a favorite among bees. On average during the trial period, fewer than 20 percent of the leaves showed mildew. Monarda ‘Achall’ ‘Grand Marshall’/Mt Cuba Center. As a result, the plant stayed lush and green until early September. So, recently researchers at Delaware’s Mt. The dark purple blooms lasted for a solid three weeks in July. Researchers also discovered that in many cases, the more the mildew the better the flower display. One scourge of the flowering perennial bee balm (Monarda didyma) is powdery mildew. No one plant performed perfectly, but there were several deserving of honorable mention. If you've grown bee balm, you know what powdery mildew is and what it can do. Cuba Center are providing a roadmap. One of the most mildew-resistant varieties available, with no winter damage, according to the Chicago Botanical Gardens Monarda trials in the mid-late 1990s. It affects several plants including lilacs, roses, zinnias, phlox and peonies. Monarda didyma, Scarlet bee balm. Cultural practices can reduce the severity of powdery mildew. Monarda ‘Purple Mildew Resistant’ is aptly named- not a single incidence of powdery mildew was observed over the three-year trial. Powdery mildew is the culprit. Monarda fistulosa ‘Claire Grace’/Mt. It typically shows up first as small white spots on individual leaves, then quickly spreads to cover most of the foliage. Unfortunately there is little that can be done in controlling or eliminating powdery mildew from plants. Lower humidity helps in the control of mildew but we both know that’s not going to happen in Indiana. Monarda fistulosa ‘Claire Grace’, one of the heaviest flower producers, ranked high for its sturdy, stems and good disease resistance. Cuba Center set out to identify which varieties offer the best resistance. I have a three year old patch of bee balm. So, recently researchers at Delaware’s Mt. The symptoms on your bee balms (Monarda spp.) Varieties that have very poor resistance to powdery mildew ( … are most likely due to powdery mildew. Bee balm plants are especially susceptible to a kind of mold called powdery mildew. Cuba researchers, this cultivar exhibited the best resistance to powdery mildew. Plant your bee balm plants far enough from each other to allow good air circulation, which will help prevent powdery mildew. The good news is that, while it may make them unsightly, powdery mildew rarely permanently damages plants. In my garden, I've always noticed that different varieties show different susceptibility to powdery mildew, and now research from the University of Vermont and Chicago Botanic Garden confirm that one variety is significantly less likely to get the disease. Is this powder mildew, or is is something else? By Charlie Nardozzi. Both spicy and sweet, its leaves smell like a bitter orange. The three-year trial evaluated each plant, each week, for quality of foliage, abundance of bloom and propensity for mildew. If given plenty of sun and well-draining soil, it will flower from mid to late summer. Monarda ‘Grand Marshall’s’ spectacular purple-red flowers and compact habit make it a great addition to the middle border. One scourge of the flowering perennial bee balm (Monarda didyma) is powdery mildew. Monarda ‘Violet Queen’ displayed excellent powdery mildew resistance. If given plenty of sun and well-draining soil, it will flower from mid to late summer. Hi, This bee balm has been in the garden for a few months and is doing well, except that it recently developed this white covering on the leaves. This site uses Akismet to reduce spam.