Trying to identify birch leaf spirea issue - Ask Extension
Hi - I planted a birch leaf spirea in April and it's not doing so well. There are rust spots and holes in the leaves, and crinkly new leaf growth. Any...
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Trying to identify birch leaf spirea issue #872637
Asked June 11, 2024, 2:10 PM EDT
Hi - I planted a birch leaf spirea in April and it's not doing so well. There are rust spots and holes in the leaves, and crinkly new leaf growth. Any help identifying the problem would be greatly appreciated!
Clackamas County Oregon
Expert Response
Thank you for your question, Stephanie. Your plant appears to have several problems, but we may not be able to diagnose all of them just through photos.
I suspect that the curling on the new growth is caused by aphids. https://ipm.ucanr.edu/PMG/PESTNOTES/pn7404.html?src=302-www&fr=4368 You're going to need to examine the plant to see if you find them.
The dark spots may be caused by this fungus: https://pnwhandbooks.org/plantdisease/host-disease/spirea-leaf-spots
The white spots may be a different fungus called powdery mildew, described here: https://pnwhandbooks.org/plantdisease/host-disease/spirea-powdery-mildew
You can take leaf samples into the Clackamas County Extension office (https://extension.oregonstate.edu/clackamas) when Master Gardeners are there (with a microscope), or send them to the OSU Plant Clinic (https://bpp.oregonstate.edu/how-submit-plant-materials). Good luck!
I suspect that the curling on the new growth is caused by aphids. https://ipm.ucanr.edu/PMG/PESTNOTES/pn7404.html?src=302-www&fr=4368 You're going to need to examine the plant to see if you find them.
The dark spots may be caused by this fungus: https://pnwhandbooks.org/plantdisease/host-disease/spirea-leaf-spots
The white spots may be a different fungus called powdery mildew, described here: https://pnwhandbooks.org/plantdisease/host-disease/spirea-powdery-mildew
You can take leaf samples into the Clackamas County Extension office (https://extension.oregonstate.edu/clackamas) when Master Gardeners are there (with a microscope), or send them to the OSU Plant Clinic (https://bpp.oregonstate.edu/how-submit-plant-materials). Good luck!
