Where are you located? Is this in sun? How much rain have you had? Have they recently been planted? Need more data from you.

Sorry - I am located in south central PA. 6a (I think). It's been really hot (for us) for the past three weeks (upper 80's) but I try to keep them watered if it doesn't rain for four or five days in a row. They were planted in April and seemed to be fine. Lots of flowers.

take a hand trowel ... and dig a hole next to the plant.. and find out if you are watering deeply enough ...

i only used black mulch once.. in the heat of summer the retained heat.. can really stress plants ...

track down the brown part.. you MIGHT find.. its all one branch.. and perhaps it was damaged anytime from grower to you ... and it was minimal.. but when the heat hit.. on a recently planted plant.. it gave up the ghost ...

if your hole indicates that it is properly watered ... and it doesnt spread ... then just rim out the dead part ...

it might be injured.. its definitely stressed.. but one thing for sure.. its not hungry.. fert is not a solution ...

ken

ps go out a couple hours after dark.. and with your bare foot.. see if the mulch is still hot ... then compare to some grass.. and that is the retained heat i am talking about ...

Thanks so much. -- will dig that hole and look for moisture.

Pieris can be tricky to get established in the Mid-Atlantic. They need consistent moisture to the roots -- but still good drainage. They also like some shade. If the plant was very root bound coming from the nursery (or wherever), then watering becomes even more tricky. You don't realize how dry the rootball can get even though the soil around it is saturated. It's often helpful when planting a root-bound plant, to score the rootball and tease some of the roots free so they will grow into the surrounding soil.

looks like pet urine to me, even if you don't have a pet it can still be pet urine.

Back in '08 I had two (of four) 'Shojo' that did that and I ultimately lost the plants- IIRC there was some question whether or not it had Phytophthora root rot, I don't know.

I moved the remaining two to a different location and they have thrived ever since- they are huge and gorgeous now plus relatively care free. Still a mystery what went wrong but it went wrong bad.

This sure looks like the problem. The other five all have just a leaf or two that are brown, so maybe I can save them by moving.

I transplanted the Annabelle hydrangea that I had in this spot for 15 years because it just got too big and blocked the sidewalk. The Annabelle loved this location, but maybe it's just too moist or too shady for these guys. This location gets sun until 1:00 in the afternoon. Coincidentally, or maybe not, I lost a pjm rhododendron last year that was newly planted nearby.

Certainly not too shady there. Maybe too sunny and hot. If the PJM is not happy, then the pieris will not be happy.

Could it be a soil pH issue? Rhodo and Pieris want acid soil and died; 'Annabelle' fine with higher pH. Probably not, would likely not manifest this way, but just raising the question.