I grew tired of watching some of my landscape ornamentals get hit with powdery mildew every summer. A buddy of mine with a lot of pathology experience (pun intended) suggested I try the fungicide tebuconazole as a preventative root drench.
So, I found this product on the shelf, Bayer Advanced All in One Rose and Flower Care. In addition to fungicide it has a systemic insecticide (imidacloprid) and some fertilizer (9–14-9). I was also sick of black spot on my roses, which this controls. The insecticide controls feeding adult Japanese beetles, a huge plus, aphids, scales, leaf miners and a host of other pests.
So I bought it and put it to the test. The general directions are 2 fluid ounces per plant, or 2 fluid ounces per 12 sq ft of general mass plantings, as a drench in 1 qt to 1 gal of water.
Back in early May I treated my roses, a 16 ft tall native flowering dogwood, ‘Mrs Moon’ lungwort, two peonies,garden phlox, woodland phlox and a mass planting of Monarda (beebalm). Interesting that every beebalm in my bed was advertised as resistant to powdery mildew! Total crap in St. Louis! I’m impressed! Especially with the lack of mildew in my Monarda bed! Directions say treat every 6 weeks, which I intend to do, because we’ve got another two months of mildew enhancing weather!