Phlox paniculata problems - Ask Extension
Good morning,Please help me to identify the problem with my tall phlox. In the beginning of spring some leaves appeared distorted, and later I noticed...
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Phlox paniculata problems #708402
Asked August 02, 2020, 11:43 AM EDT
Good morning,
Please help me to identify the problem with my tall phlox. In the beginning of spring some leaves appeared distorted, and later I noticed that most of them became partially yellow. This is not a mildew, since I did manage to cure it with copper fungicide. Right now in July they still bloom, yet the stems look weak and unpleasant. Thank you!
Please help me to identify the problem with my tall phlox. In the beginning of spring some leaves appeared distorted, and later I noticed that most of them became partially yellow. This is not a mildew, since I did manage to cure it with copper fungicide. Right now in July they still bloom, yet the stems look weak and unpleasant. Thank you!
New York County New York
Expert Response
Hello and thank you for contacting us.
There are at least two possible causes of the yellowing leaves on your phlox. The first would be a nutrient deficiency, which can be determined by a routine soil test. The other possibility is aster yellows, a disease carried by pests. The distorted leaves and weak stems would seem to indicate aster yellows. Unfortunately, there is no cure for this disease and the control is to remove and destroy all affected plants and plant debris.
You can read more about the disease here:
http://www.missouribotanicalgarden.org/gardens-gardening/your-garden/help-for-the-home-gardener/advice-tips-resources/pests-and-problems/diseases/viruses/aster-yellows.aspx
There are at least two possible causes of the yellowing leaves on your phlox. The first would be a nutrient deficiency, which can be determined by a routine soil test. The other possibility is aster yellows, a disease carried by pests. The distorted leaves and weak stems would seem to indicate aster yellows. Unfortunately, there is no cure for this disease and the control is to remove and destroy all affected plants and plant debris.
You can read more about the disease here:
http://www.missouribotanicalgarden.org/gardens-gardening/your-garden/help-for-the-home-gardener/advice-tips-resources/pests-and-problems/diseases/viruses/aster-yellows.aspx
