One of our mature hydrangeas has some stems that are dying

Question: The plants are more robust than usual, but one has a few stems that are drooping and then dying. I don't see any insects. The usual gray aphids curl up individual leaves but are a minor problem. This problem of the past week has one stem off a trunk drooping and dying. It's spotty but I don't want it to worsen. I've watered, and we had that nice rain the other day. These bushes used to droop when not watered but need less watering as they've matured. This die back is worrisome because I've not seen it before. If it is a pest of some kind I'd like to do something before it gets worse. Thanks.

responder: Steve Miles  Master Gardener, Hennepin County MN (I answer using human intelligence, not AI)  Replied July 06, 2023, 2:56 PM EDT
response: Thank you for writing. I need a tight closeup of a stem going to a dying  (but not dead) leaf. How do you water these?  Are they in an area with an automatic sprinkler.  Edema from overwatering can do this.  I need a close up of a drooping green leaf. Here is one list of diseases but I am inclined to think this is not viral, fungal, or bacterial.  https://gardenerspath.com/how-to/disease-and-pests/hydrangea-diseases/

responder: The Question Asker Replied July 06, 2023, 6:49 PM EDT
response: I hope this helps. The page wouldn't let me upload all four photos. I haven't watered these hydrangeas as often this summer because they've not shown the characteristic drooping from being thirsty. So they've not been overwatered. I watered when I noted the drooping stems on the one plant. We have eight. All seemed very robust and this one is mostly OK. One plant gets collapsed during downpours when the gutters overflow, but is otherwise OK.  I also haven't needed to be aggressive with those small gray aphids that turn a leaf here and there in on itself. That problem seems held in check by the species that eats the aphids.

responder: The Question Asker Replied July 06, 2023, 6:50 PM EDT
response: Two more photos.

responder: Steve Miles  Master Gardener, Hennepin County MN (I answer using human intelligence, not AI)  Replied July 06, 2023, 10:43 PM EDT
response: Those bottom two pictures look a bit like anthracnose, a fungal disease seen in hot weather when the plants are being sprinkled from above so that soil bacteria bounce up to the lower leaves. https://gardenerspath.com/how-to/disease-and-pests/anthracnose-hydrangea/ For now, cut off all leaves that are within three inches of the ground.  Sterilize your pruning scissors with lysol at the recommended dilution.   Send me new pictures a week after you do this. Best

responder: The Question Asker Replied July 06, 2023, 11:03 PM EDT
response: The leaves that are dying are up near the end of the respective branches. None are near the ground. Is this still your tentative diagnosis?On Jul 6, 2023, at 9:43 PM, Ask Extension <<personal data hidden>> wrote:

responder: Steve Miles  Master Gardener, Hennepin County MN (I answer using human intelligence, not AI)  Replied July 06, 2023, 11:17 PM EDT
response: To me, the most interesting photos are these.  Notice the brown lesions in the stems and in a leaf.  This looks like botyris blight.  https://extension.psu.edu/hydrangea-diseases

responder: The Question Asker Replied July 06, 2023, 11:22 PM EDT
response: Thanks, I’ll ask Sunnyside Garden Center for a fungicide and I will remove the affected stems tomorrow morning.Thanks!Er-Hwww.er-h.comHere’s what I do when I’m not looking at my garden… I’m an illustrator.On Jul 6, 2023, at 10:17 PM, Ask Extension <<personal data hidden>> wrote:Dear Eric, here's the response to your question:To me, the most interesting photos are these. Notice the brown lesions in the stems and in a leaf.  This looks like botyris blight. https://extension.psu.edu/hydrangea-diseases Need to reply to the expert? Click the link below, or simply reply to this email.Click here to view #0109230Steve Miles  Master Gardener, Hennepin County MNI am always happy to receive follow-up questions if I do not fully address your question.Sterilizing pruning tools prevents disease. https://extension.umn.edu/planting-and-growing-guides/clean-and-disinfect-gardening-toolsWe hope this response has sufficiently answered your questions. If not, please do not send another email. Instead, reply to this email or login to your account for a complete archive of all your support requests and responses.<Screenshot 2023-07-06 at 10.08.34 PM.png><Screenshot 2023-07-06 at 10.08.01 PM.png>

responder: Steve Miles  Master Gardener, Hennepin County MN (I answer using human intelligence, not AI)  Replied July 07, 2023, 12:43 PM EDT
response: Lovely illustration.   When I am not gardening, I am getting more plants. Do you know about tree lilies? All best