Give it a try. ‘Shortwood’ was discovered in a planting of ‘David’, another long-standing mildew-resistant phlox. Phlox prefer an compost-rich, moist, moderately acidic, well-drained soil. Many varieties that we carry have a high resistance to powdery mildew. Just about every phlox is touted as "mildew-resistant" but beware. Space plants adequately for good air circulation to prevent or reduce powdery mildew problems. Blooming for weeks from mid to late summer, the flowers are rich of nectar and visited by hummingbirds, butterflies or birds which adore them. Phlox are a favorite, old-fashioned plant in perennial gardens. Best flowering on sturdy healthy plants is in full sun. Phlox are intolerant of dry soils and summer dry spells. By the middle of the season my phlox look terrible and have lost most of the leaves on the bottom half of the plant. 8 years ago. Prolific and mildew resistant, Phlox paniculata 'Eva Cullum' features large, bright pink blooms with tiny dark pink eyes that float atop the attractive dark green foliage. First, there are many strains of the powdery mildew that attacks phlox and varieties may be resistant to some strains but not all. Mildew infections can be quite dramatic when they have a strong hold on phlox plants, and that nasty experience has motivated breeders to work on building resistance in the plants. junco1102. The right location is an absolute when growing garden phlox. But the most effective way to avoid mildew disease is to plant resistant phlox cultivars. What are the best phlox plants available, and the most mildew-resistant varieties? * Phlox carolina 'Reine du Jour' flowers white with a pink eye … I love phlox, but have had a real problem with powdery mildew (at least I think it is powdery mildew) in my garden. These phlox combine good health, strong habits and high flower production. Answer. Mildew resistant phlox? Growing cheek by jowl with dozens of susceptible cultivars, it was astonishing that we never found a spot of mildew on its leaves. Sweetly fragrant, they are borne on stiff, upright stems which seldom need staking. "The following phlox were listed as showing good powdery mildew resistance in the Chicago Botanic Garden evaluation. These dwarf varieties are more compact than the Tall Garden Phlox choices but they still produce large flower heads. Phlox ‘David’ is a great cultivar that’s powdery-mildew resistant. Phlox paniculata was perhaps the most prominent plant in perennial gardens from the turn of the 20th century through the 1940s. In the end, it took top honors for exceptional performance and superior resistance to powdery mildew.