The only other thing I can think of might be spider mites infesting the underside of the leaves - or the aftermath of an infestation if you didn't see anything on your inspection. This tends to occur if the soil is hot and dry - a little soil amendment for sandy soils would go a long way as well as additional watering should help them grow out of it.

Agree. Or possibly some other type of sucking insect.

Insects with piercing/sucking mouthparts feed on young leaves and that causes the leave to grow distorted as it matures. Unless the damage is quite extensive or persists for some time, it is recommended to tolerate the insects having their meal.

Thanks,

I was thinking the same thing, as far as it being an insect, but there were no signs of webbing and I did not see any of the insects upon inspection. Once again, I know that does not mean they have not been there. I did not think about the propensity of an insect for new growth, so that makes sense.

It has been very dry in Mankato this spring and summer, I know that this contributes to the insect issue, mites in particular. Next time I go there I will see if I can bring some mulch to help retain some of the soil moisture, her gardenes are fairly packed and digging in an ammendment is a good idea, but I would have to help her with that earlier in the season.

Thanks for your input, Helen.

same problem.

mine were snipped off by deer quarter way down.

I sprayed with liquid fence. New growth leaves all rolled up. Just like aphids but i know aphids and there aren't any. No mites either. While it's been dry i water almost every day. Leaves are green , no sign of disease.

Never seen this before

I am up here 300+ miles northwest of the metro area, and I noticed the same thing on my phlox today, but just 2 stems on the plant are doing it. And another phlox about 4ft away is fine.