I certainly wouldn't cut it down until frost gets it. Mildew is more environmental, not something that will spread to other plants and cause a lot of longterm damage. If it did, the lilacs around here would have become extinct decades ago. They're covered in it almost every year. Some years I have it on my phlox or fall asters, others I don't. I think there may be some sort of spray for this, but I've never used it. It is kind of ugly though.

Kevin

Enjoy the blooms! At least, that's what I would do. As a matter of fact, that *is* what I do, lol! But that's because I never usually get around to doing anything about the mildew until after the blooms have come and gone anyway. Although, knock on wood, my phlox isn't as bad as usual this year - so far.

You can always cut the blooms, remove the foliage from the stems, and enjoy them in a vase inside.

Dee

That's just what happens most of the time with phlox paniculata....they get moldy. Doesn't seem to affect the blooms nor the health of the plant....they just get powdery mildew.
Try to remember to spray them with sopme baking soda next year about the first week in July and again a week later. But if you forget....they will still bloom.
Linda C

Mine look pretty good for the most part, but the sign's of mildew are beginning to start appearing, on my phlox and monardas. You can make a concoction in a spray bottle of 2/3 water, 1/3 non sudsy lemon ammonia and a drop of Ivory dish detergent. Shake and spray the foliage daily or every other day for about 10 days. This cleared up my mildew a few years ago, and I swear by it. I would spray at dusk and avoided the blooms as best I could.

Ken I use this mixture to rid my phlox of white mildew(mold). Mix about 3 tablespoons baking soda, 1/2 cup milk (my recipe says low fat) with a gallon of water. Spray every 7 days. Works like a charm.

The baking soda has something in it that kills the mildew. The milk makes the baking soda stick to the plant.

A lot of people have had success controlling mildew with a 10% milk/water spray; you don't need baking soda. There have even been agricultural trials demonstrating its efficacy. If you do a search on milk in gardenweb, or google "milk mildew," you will find a lot of information on this. It's the least nasty thing you can spray; I always found baking soda to be somewhat phytotoxic. The link I'm giving is from someone who used milk specifically for mildew on phlox.

Here is a link that might be useful: using milk to control mildew

Hi - In spring spray your gardens with 1 part skim milk to 9 parts water. Tests some years ago showed that this stops powdery mildew from forming - this has worked for me for years. This spring I didn't get around to spraying the gardens down and sure enough my monarda, asters, phlox, dahlias, lilacs and anything in the mint family got great coverings of powdery mildew! This also works wonders for keeping PM off grape vines. You can use only skim milk - it makes no difference using the higher fat content milk - except that it reeks!

Here is the link to the original research in 1999. http://www.pioneerthinking.com/tv-mildew.html
You can do a google search on this and find out more whenever you want.
Cheers from Michigan

Here is a link that might be useful: Powdery Mildew & Milk

Thanks everyone! I am going to try the milk idea. Perhaps I won't wait till next year as I don't see how it could hurt. Perhaps it will save some of the plants greenery for the rest of the season.

Ken

Thanks everyone! I am going to try the milk idea. Perhaps I won't wait till next year as I don't see how it could hurt. Perhaps it will save some of the plants greenery for the rest of the season.

Ken

Yes, there's no need to wait. It could at least halt the spread of the powdery mildew. Please let us know if it helps.

Ha! I sprayed mine well after the mildew got a hold on my phlox - they do look a bit dopey as they have 4 ft stems and there is about 5" of greenery and then blooms on the top! The milk stopped it in its tracks! Same with the monarda ... even tho I only have TWO blooms on a whole huge plot of monarda because, even tho it is written that monarda are deer resistant, the deer took off all the tops except for these two tops! I may still get plenty of blooms on those tho as they are bushing out and growing well now - I never thought of cutting back monarda before but I sure will do it (just like with mums) at the beginning of the season!

Spray away!

My creeping phlox recently died after a heavy mildew infestation. I'm not sure if the mildew killed it, but I'm sure it harmed its ability to photosynthesize and helped to do it in. I'm not of the opinion that mildew is unsightly but harmless.

The milk/water mixture sounds like a good idea. I don't get much mildew on my Phlox p., but I do get a lot on the Monarda, Lilacs, and this one particular peony (??).

The fact that the Phlox doesn't get much mildew might have something to do with being located in a very windy garden so they get plenty of air circulation. Also I have several with variegated foliage and I've never seen any mildew on those.

Don't do any overhead watering, this may be making the situation worse. Try to just water at the base of the plants like you would do with a rose. Good luck -Jessica

I only have one phlox..Nora Leigh with the variegated foliage. This is it's second year and is just starting to bloom for the first time. I didn't stake it and as soon as the blooms opened it flopped over and I had to tie it up yesterday.

It hasn't any mildew on it at all which I am happy about. I don't know if that is because of the plant or the weather. We have had an unusally moderate summer and not the usual 'mildew producing' weather. so I guess next year I will see again whether it will mildew on me.

Love the plant btw, The variegation is gorgeous. Not sure if it is fragrant yet.