I've always had some powdery mildew on phlox usually later in the season.This year being so dry starting in May,the phlox got horrible mildew when it was still little.I've concluded the drought caused it.Reason being,I planted a new Red Riding Hood Phlox where I keep other plants well watered,just feet from the hydrant & it is blooming nice without mildew.The same variety planted in a dry spot in the yard got mildew as it came out of the ground. I think the plant died now. Another phlox near some daylilies I kept watered has been mildew free. My friend says that drought has nothing to do with it that it is just the variety. I think the same thing about zinnias. When they get dry & stressed they start to mildew. I've gotten that black spot fungus on my zinnias late in the season. Anyone had experience with growing these flowers? sewNsow
While I have not had powdery mildew in years you could try milk at a ratio of 1 part milk to 9 parts water and spray it on the phlox. There is also a baking soda solution. Jerry
SewNsow- I agree with your assessment. I think phlox is susceptible to mildew, but particularly so when stressed. I have noticed some plants succumbing during drought. I also have noticed that some plants are more resilient than others. I have had good luck with 'David', a tall white phlox. Other phlox are more susceptible, even if given the same amount of water. I have just begun pulling those and disposing of them.
Carolyn--So sorry. Nothing looks sadder than a phlox covered with mildew. I wonder if adding those water retaining granules to the soil when planting would help? I don't know how long they last. I used some for a Hakonechloa grass that I wanted to plant in a less than ideal location. I think it helped, but maybe the granules only last the first season and by then the plant has a good set of roots. You could try it. Or try 'David'. He's pretty good! It is a white white phlox without a hint of pink or yellow. Very pretty. And tall. Gives a stately aspect to the garden. Cheryl--Mildew hasn't reared its ugly head here yet (NE), but when it does, I will post a photo.
Grrrr.....I just checked and unfortunately my phlox & bee balm already have mildew. Here are some photos. Mildew on beebalm ( photo / image / picture from Cayuga Morning's Garden ) Mildew on phlox. Sickening, isn't it? ( photo / image / picture from Cayuga Morning's Garden ) More phlox leaves ( photo / image / picture from Cayuga Morning's Garden ) The leaves will eventually turn yellow & die. ( photo / image / picture from Cayuga Morning's Garden ) But, on a bright note, here is 'David'. Gorgeous, isn't it? ( photo / image / picture from Cayuga Morning's Garden ) And here is 'David' with the daylily 'Rocket City' ( photo / image / picture from Cayuga Morning's Garden ) And finally, here is 'Davids' foliage. No mildew as yet. ( photo / image / picture from Cayuga Morning's Garden )
Another thought. I am sure this goes without saying, but if/when you get mildew (as with all diseased plant material) never put it in your compost heap. Dispose off your property ?in the trash?
Oh, CM, My leaves are SOLID white. Yours look good ( photo / image / picture from carolyn keiper's Garden ) I did spray it with a copper product last week and I see some new growth that is green now, but I think I will move it this fall if I remember.
Mine look like Carolyns.Solid white & started when little. I know I should have cut it off but got most cut off this AM.Even my white which is supposed to be David is affected. Wonder if these whites are from reseeding? Doesn't seem to matter about circulation. sewNsow
Wow Carolyn, that is spectacular in a creepy kind of way. I think I would be tempted to just remove all those leaves and hope the fresh growth at the top can sustain the plant. Either that or cut the plant down to the soil & let it start again. I did that once to a badly infected plant and it did grow fresh new leaves. Good luck. You make me realize I have nothing to complain about.
:-D Yep Cayuga Morning, I thought yours looked good, too. I dusted it with dragoon dust and I do see new growth coming. I think I will move it this fall, though. It gets no direct sun or very good air circulation, either.
Even the David varieties which are supposed to be resistant still get the powdery mildew. I've grown hundreds of them.
