Mildew-resistant, free-flowering, and very long-blooming, this annual is a superb choice for groundcover, mass planting, street planting, edging, bedding, and containers. Article excerpt. I never have seen one spot of mildew on these. HERALDED IN catalogs as an annual that provides continuous bloom until first frost, the flamboyant zinnia … Benary’s Giant mildew resistant … While it's not great for cutting, narrowleaf zinnia doesn't need deadheading to keep blooming either. Order now at Park Seed. Read preview. Unlike common zinnia, it's a mounding plant and grows about 16 inches tall and wide. This was the first mildew-resistant variety developed for the cut flower trade about 15 years ago. A 2006 All-America Selections award winner, this vibrant plant features semi-double, 3- to 4-inch-wide, scarlet-rose blossoms with warm yellow edges and, like other zinnia hybrids, is remarkably mildew resistant… ... One of the most common diseases to afflict zinnias is powdery mildew, especially in hot areas with humid summers. It resists mildew and leaf spot and is much more drought tolerant than common zinnia. By Swezey, Lauren Bonar. They have better mildew resistance than older large dahlia-flowered zinnias, are especially attractive to butterflies, and are my favorites for striking bouquets. My favorites for cutting and display that I have grown from seed many times are ‘Benary’s Giant Zinnia’. Of nine kinds tested, four came out winners . Award-winning bedding Zinnia from seed with big double blooms in bright orange-red. If this is a serious problem, plant the most disease resistant … The blooms are smaller, about an inch wide, but it flowers profusely. Mildew-Resistant Zinnias .