ETA: The original plant from which these cuttings came is completely normal looking.

More pics this evening, and powdery mildew appears prevalent in Turk's Caps. Is PM supposed to leave a powder when you rub on it?

Look how it goes up the stems:

Nothing rubs off.

Close-ups of the leaves -- last one, the underside.

Wikipedia article says white splotches/spots on upper surfaces of the leaves are a telltale sign:

But there are no such white splotches on mine.

Did you ever figure out what this was?

I'm in Houston too and see some strange discoloring on my new leaves that look a bit like this but on two Altheas.

This forum was my last hope, actually, so nothing definitive. I can't seem to get a handle on whether the powdery spores of PM actually will rub off on my hands, as this stuff on my plants doesn't. In many ways, it does seem to fit the PM descriptor in terms of spores tending to feed only on new, tender growth. This explains why the substance seems to go along the stems and stop right at the mature leaves. On the more tender shoots, it seems to barrel right on through.

I look more closely yesterday, and the original/mother plant (from which these cuttings came) is also showing signs of this stuff on many of the stems. While that plant isn't pushing much new growth (such that I'd be able to note malformed leaves), I do notice it's not flowering much. A few branches are ~ 5'-6' tall, but there might be only a handful of blossoms.

Anyone out there in Houston Land with Turk's Caps that are in full bloom right now? If so, do you grow in full sun, morning sun only, shade...? My largest plant gets dappled morning sun for about an hour, then pretty much shade the rest of the day. I'd read these should do well in shade. TIA.

I'm watching this thread with interest, but can't help with a diagnosis. Being in a drier climate my turks caps don't seem to be subject to powdery mildew; at least not enough to be noticeable.

Ironically, at least from what I read, powdery mildew takes hold during hot, dry conditions. So, some advice is to just frequently hose down the plant, but during midday so the leaves have time to dry out -- so moisture-loving diseases won't become a problem. My fence-neighbor's crape myrtle is showing signs of PM on the leaves, but the branches are too high up for me to rub them and see if anything comes off onto my fingers. Are your Turk's Caps blooming like crazy right now? I wonder if the fungus is affecting flower production....sad. This was supposed to be such an easy plant.

I'm just north of Austin and have never seen any PM on anything but Crepe Myrtles in extended days of heavy rains and clouds. My currently blooming Turk's Caps (those in full sun and in full shade) have no such issues. Blooming as much as they ever have. My TC plants out back in total shade have never gotten mildew, which is why I think what you have there isn't mildew. Sorry I'm not more helpful with a diagnosis for what you DO have there, Javiwa. If it's PM, my dad always sprayed all parts of the plants with ordinary dish liquid soap in water, being careful to get tops and bottoms of all leaves and stems. It works, as I had to treat a Crepe 2 years ago for it. You could do the soapy wash and when it is dried. you could try spraying with neem oil to go after insects. Perhaps a hit of fungicide spay wouldn't hurt either. My tact in the garden has always been "when in doubt, treat with everything and maybe one of them will kill what is causing the damage. I just can't seem to learn what the various diseases and insect damage really look like, other than just a few of them.

Thanks for coming to my rescue yet again, buttoni. :) No surprise, but the more I plant, the more issues I encounter: but, all good! Very helpful to know the TC should be in full bloom -- definitely something going on with even the original plant. Very frustrating, nevertheless. Last resort, I could email the county extension. Will let you know what I find out. TY!

I appreciate Buttoni's input also. I just now checked on the Turk's caps around here. This is a bunch that grows under oak trees in James' yard next door yard. It never gets watered, but to its credit it lives and blooms ...

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It has a lots of buds and small flowers ...

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Frankly I've never been a big fan of Turk's cap because they seem to always look wilted.

In contrast this 'fire bush' I planted next to their driveway near to the 'hell strip' in full sun, including brutal afternoon sun and heat reflected off the street, is never watered either and rarely wilts. A more worthy plant in my estimation ...

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However, I am growing the pink form in the back yard that Patty gave me. It gets watered but the flowers are smaller than usual in this heat ...

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I didn't notice the bug until I enlarged the photo. Hmmm, is it one of the kissing bugs?

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So there you have it. It will be interesting to see what the county extension might have to tell you.

I sought out and planted TC because I was looking for a nectar plant that would do well in the shade. The pink variety is on my list. :) I shall not be deterred!

I have a bush of the pink in my smallest back garden. It draws butterflies occasionally and is in dappled sun.

It nor my red ones out front ever wilt, perhaps because our sprinkler runs ever 3 days and hits all of my TC plants directly. :)

I have never fertilized my Turk's Cap in 4 years here. You folks think I should and that will boost number of blooms?

Gorgeous plants, buttoni. I'll let others chime in about fertilizer: this is my first year w/ TC, so I'm just following along. :) I know a lot of folks say they don't bother with fertilizing perennials, as long as the soil is fertile w/ compost, etc. Some will give annuals a quick bump.

We have many of these around our yard descended from a few planted on our lot 20+ years ago. We've only seen this problem on 2 or 3 plants over the years. This Smarty Plants post provides an accurate description and think they're probably right on the PM diagnosis. In our Dallas climate, it usually clears up after a bad season. Our 'John Fanick' summer phlox got it bad this year for the first time, but has not shown up in the TC. Our TCs have been in heavy bloom for a couple weeks; these are in mostly shade:

They grow reliably in full sun through heavy shade. Though like them better with some shade because they seem to remain a bit smaller and have less leaf scald or the wilting Roselee mentioned. Here is one in full sun for comparison:

We keep the ones in full sun because they get huge (6-7 ft) and are loved by the hummers.

bostedo: Wow...your TCs are absolutely flocked with blooms! I think all year long, my largest plant (now topping 6' tall and very healthy) as had that many blooms all year long, combined -- one here, two there, etc. Now that the sun is moving more southerly, the edge of the TC gets a few hours of sun. Still, even the ones in shade (w/ morning dappled) should be blooming.

Ohhhh...this is the larger/original plant's first year (planted last October). I took cuttings from it and rooted them in early spring, and planted them ~ February/March. We here in SW Houston have been the opposite: dry spring, dry/hot summer.

I think you're right Bostedo about the 3-year wait to reach full potential. In the lower picture in my above post, that plant is pretty much in full sun most of the day but is shielded by oak tree shade in the hottest afternoon west sunset, and it has never wilted for this reason, I suspect. It's in my front lawn bed that is on the south side of my home, gets about 4 hours of full sun a day, but the particular photo above was taken after dinner when it's in the afternoon shade from my neighbor's oak trees. It just thrives in that location. I cut it back to the ground every year and i comes back bigger and with more blooms. Hummers are on this one most days.

The ones below live in the back yard garden in part to full shade. Hummingbirds go after them in all locations. First photo plant is in dappled shade most of the day. It's right under an oak tree and is just in its second season of growth.

As you can see, the plant cluster below (several plants) are in full shade most of the day, are kind of hidden by a nandina on the left and a huge rose bush on the right. They have been here the 4 years we've owned the house, I guess planted by the previous owner. They don't bloom a lot in such deep shade.........but the hummers still find them and enjoy what blooms they have each year.

Oh, and I think I've found out why the site randomly won't let me upload my photos. Don't know why it doesn't just say so (other forums software does), but I think it has to do with photo size. If the MB load is too large, it won't upload direct from my hard drive; if it's reduced 30%, it will. I just sized these down 70% with MS Paint and they all uploaded just fine. I'm glad I figured out THAT rather annoying issue!

I am expereincing the same problem as original poster in North Texas.

Has any solution ben found in the past 3 years? Any updates on original poster plants?

What a blast from the past! IIRC, I pruned back the affected branches, but new growth had similar fuzzies. I guess I left them alone and conditions improved -- this pic was snapped October 2021. All TCs have been thriving ever since, and I never fertilize these (or pretty much anything in the yard).

@bostedo: I picked up a Fanick summer phlox a couple of autumns ago, and only this year has it finally grown larger and putting out blooms. It's in full sun from noon onward, so I hope I didn't plant in the wrong spot -- too late now!