Brown patches on hydrangea leaves - Ask Extension
We recently purchased two “Pinkie Winkie” hydrangea plants. Over the past week, they have developed brown patches on their leaves. Curiously, ou...
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Brown patches on hydrangea leaves #876022
Asked July 05, 2024, 3:45 PM EDT
We recently purchased two “Pinkie Winkie” hydrangea plants. Over the past week, they have developed brown patches on their leaves. Curiously, our older established blue and pink hydrangeas have not been affected. Any information or assistance you can give me should be greatly appreciated. Thank you.
Anne Arundel County Maryland
Expert Response
This is not concerning. You can pinch off those leaves if you like.
The most important thing you can do for your new Hydrangeas is to keep them well-watered for the first 18-24 months in the ground.
It's possible that what you are seeing is leaf scorch, which many plants are experiencing now, being stressed by the high heat and lack of rain.
Be sure to monitor for watering needs.
The fact that established hydrangeas are unaffected suggests under-watering or scorch since these are newer plants with a smaller root system.
Here is our watering information:
https://extension.umd.edu/resource/watering-trees-and-shrubs/
Christine
The most important thing you can do for your new Hydrangeas is to keep them well-watered for the first 18-24 months in the ground.
It's possible that what you are seeing is leaf scorch, which many plants are experiencing now, being stressed by the high heat and lack of rain.
Be sure to monitor for watering needs.
The fact that established hydrangeas are unaffected suggests under-watering or scorch since these are newer plants with a smaller root system.
Here is our watering information:
https://extension.umd.edu/resource/watering-trees-and-shrubs/
Christine
Many thanks for the above reply. Since that question was submitted, our hydrangeas have now developed holes in several of their leaves. Could this possibly be heat related, as well or is it something more concerning. Many thanks for your help, Cathy
Here is our page on Hydrangeas. Yours is a type of panicle Hydrangea (H.paniculata):
https://extension.umd.edu/resource/hydrangea-identify-and-manage-problems/
The holes you are seeing are not heat-related but look like minor damage from an insect- it could be from a beetle, but I see some damage in your second photo that looks like it was done by a pest with rasping mouthparts a while ago and the dead area are not just falling out, which is normal.
We don't recommend any treatment regardless. Those leaves are still healthy to easily feed the plant though photosynthesis.
To have healthy landscapes and environments, we use what is called IPM to manage them, which stands for integrated pest management. Nurseries and garden center generally want to have plants with perfect leaves to be able to sell them, which requires the use of pesticides, for even minor problems.
For our home landscapes though, we shouldn't expect to have plants with perfect leaves and accept a certain amount of imperfection from disease/insects/abiotic factors, as we aim to have minimal toxic chemicals released into the environment to keep us and our landscape healthy. Even when action does perhaps need to be taken, we start with least toxic alternatives.
We are always happy to advise, so thank you for your questions.
Christine
https://extension.umd.edu/resource/hydrangea-identify-and-manage-problems/
The holes you are seeing are not heat-related but look like minor damage from an insect- it could be from a beetle, but I see some damage in your second photo that looks like it was done by a pest with rasping mouthparts a while ago and the dead area are not just falling out, which is normal.
We don't recommend any treatment regardless. Those leaves are still healthy to easily feed the plant though photosynthesis.
To have healthy landscapes and environments, we use what is called IPM to manage them, which stands for integrated pest management. Nurseries and garden center generally want to have plants with perfect leaves to be able to sell them, which requires the use of pesticides, for even minor problems.
For our home landscapes though, we shouldn't expect to have plants with perfect leaves and accept a certain amount of imperfection from disease/insects/abiotic factors, as we aim to have minimal toxic chemicals released into the environment to keep us and our landscape healthy. Even when action does perhaps need to be taken, we start with least toxic alternatives.
We are always happy to advise, so thank you for your questions.
Christine
