Geranium Problems - Ask Extension
I live in Copley. Every year some of my zonal geranium's die when the weather gets humid and rainy, generally early August. They are planted in full...
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Geranium Problems #847203
Asked August 24, 2023, 7:39 PM EDT
I live in Copley. Every year some of my zonal geranium's die when the weather gets humid and rainy, generally early August. They are planted in full sun. Prior to planting, I till the soil and work in Osmocote then fertilize once a week with a water soluble fertilizer. Attached are pictures of 3 different geraniums. Not sure if this is fungus, blight, blackleg, or something else. What do you think?
Summit County Ohio
Expert Response
Hi Jim, I apologize for the delay in getting you a response. We're working on finding the right expert and should have an answer for you soon
Hi Jim
Thank you for your question and pictures. While anyone can see that your geraniums are indeed struggling, I cannot diagnose with any certainty.
According to the resources I have found, the pictures you have shared seem to look most like nutrient uptake issues. This seems surprising, since you apply fertilizer at planting and during the growing season! We always recommend a soil test, especially if the problem is persistent. Here's the link;
https://ohioline.osu.edu/factsheet/hyg-1132 Just scroll until you find the instructions on "how to" and keep scrolling to locate the lab options.
Geranium growers indicate that watering issues can influence zonal geranium's health in a negative way. Water (and soil) with high pH, watering at the base, over watering (mother nature can do this sometimes. Recommended pH is slightly acidic, 6-6.5)
Root rots can look similar to your sickly geraniums. It would be worth it to dig one of your plants to examine the roots. Replant if it looks healthy; full and white rather than mushy. This info may be helpful to you.
Click the "submit sample" option on the bar: upper left and follow those instructions.
Although the mystery is not solved, I hope these resources are useful to your future success growing great zonal geraniums.
Thank you again for using the Ask Extension online service.
Thank you for your question and pictures. While anyone can see that your geraniums are indeed struggling, I cannot diagnose with any certainty.
According to the resources I have found, the pictures you have shared seem to look most like nutrient uptake issues. This seems surprising, since you apply fertilizer at planting and during the growing season! We always recommend a soil test, especially if the problem is persistent. Here's the link;
https://ohioline.osu.edu/factsheet/hyg-1132 Just scroll until you find the instructions on "how to" and keep scrolling to locate the lab options.
Geranium growers indicate that watering issues can influence zonal geranium's health in a negative way. Water (and soil) with high pH, watering at the base, over watering (mother nature can do this sometimes. Recommended pH is slightly acidic, 6-6.5)
Root rots can look similar to your sickly geraniums. It would be worth it to dig one of your plants to examine the roots. Replant if it looks healthy; full and white rather than mushy. This info may be helpful to you.
https://portal.ct.gov/CAES/Plant-Pest-Handbook/pphG/Geranium-Zonal-or-Ivy-Pelargonium
Honestly, the only sure-fire way to solve this mystery is to send a sample to the C. Wayne Ellet Plant and Pest Diagnostic Clinic for a lab test. Here is the link for instructions on how to submit a sample:
Click the "submit sample" option on the bar: upper left and follow those instructions.
Although the mystery is not solved, I hope these resources are useful to your future success growing great zonal geraniums.
Thank you again for using the Ask Extension online service.
