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Dogwood leaves and branches are dying #795414

Asked June 11, 2022, 1:20 PM EDT

One of my dogwoods is sick starting last year, with the leaves growing in wrinkled, and then twigs starting to turn brown and all the leaves dying. Is this some type of canker, is there any treatment I can try? See representative photos; let me know if further info/photos would help. Thank you!

Hennepin County Minnesota

Expert Response

I am unable to tell from the pictures alone what is causing the leaves to be wrinkled, and twigs starting to turn brown and finially all the leaves dying. Please look for small holes in bark with brown colored frass coming out of the hole. Also look for series of closely placed round holes in the bark.  Leaves above the tunneling wilt and die, followed by dieback of the mined twigs.  Is the bark on affected branches  darker, cracked, or blistered at the site of the canker?
https://apps.extension.umn.edu/garden/diagnose/plant/deciduous/dogwood/
  Did you mulch or water the plant during last season drought?
I will waiting for the reply to these pictures.  Please send closeup pictures of anything that you discover.
Pat M MN master gardener and TCA Replied June 11, 2022, 3:16 PM EDT

Thanks for the quick response! I checked closer and don't see a series of holes, and definitely didn't see holes with brown frass. The dying and dead twigs do seem darker, and I saw a few splits or blisters, but I wouldn't call it cracked looking. A couple of the affected branches almost seemed bleached. I'm attaching more zoomed in photos for more examples and details.
I did water the shrub through the drought last year, probably not as much as I should /could have. But I did the same amount of watering for two other dogwoods and they're not suffering.
Looking at the link you provided, I wonder if this is Botryosphaeria canker?
Thanks again, am looking forward to your thoughts.

The Question Asker Replied June 12, 2022, 5:07 PM EDT

Photos here

The Question Asker Replied June 12, 2022, 5:10 PM EDT

And a couple more 

The Question Asker Replied June 12, 2022, 5:11 PM EDT

Thank you for this reply. Botryosphaeria canker is caused by a fungus called Botryosphaeria dothidea. Both freezing  temperatures and drought predispose dogwood plants to the opportunistic fungi that cause cankers and stem dieback.  When dogwoods are starting to deacclimate from their winter hardiness are suddenly hit by a late spring frost ( around 28F) plant tissues are injured.  This fungus invades through wounds, possibly growth cracks, and weak areas of the wood. Drought stress may also lead to Botryosphaeria canker in dogwood  To confirm a fungal canker, look for fruiting bodies of the fungus in the lesions. They appear as black, pinhead-sized structures embedded in the face of the lesion.
https://horticultureforhomegardeners.ca/2021/04/07/botryosphaeria-canker-of-red-twig-dogwood/
Pat M MN master gardener and TCA Replied June 12, 2022, 5:42 PM EDT

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