Yellow Lilac Leaves - Ask Extension
Hello. I planted three lilacs, 5’ apart , about four years ago. Just this summer one of them developed yellow leaves with some brown areas. It...
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Yellow Lilac Leaves #847096
Asked August 24, 2023, 11:03 AM EDT
Hello. I planted three lilacs, 5’ apart , about four years ago. Just this summer one of them developed yellow leaves with some brown areas. It could be a watering issue but it’s happening to only one of them.Any ideas or suggestions? Thank you.
Boulder County Colorado
Expert Response
Hello Aleta,
Thank you for contacting Ask Extension about your problem with one of your 3 lilacs.
The 2 probable issues are a bacterial infection by
Pseudomonas syringae or a fungal infection by a fungus in the Pseudocercospora. It is very difficult if not impossible to differentiate the two without a diagnostic examination. You can bring a sample of your lilac to the Boulder County Extension Office on Tuesdays and Fridays from 9 to noon. Bring in a several complete branches and pictures of all three plants as well as a sample from a plant that is not infected.
After you take these samples, it is important to cut back all dead and diseased tissue and dispose of it in the trash. Do not compost. After diagnosis you will be advised about other treatments that will help.
Lilac Bacterial Blight | Horticulture and Home Pest News (iastate.edu)
Lilac Pseudocercospora Leaf Spot | Horticulture and Home Pest News (iastate.edu)
What's wrong with my lilac? Summer foliar diseases on lilac | Illinois Extension | UIUC
Thank you for contacting Ask Extension about your problem with one of your 3 lilacs.
The 2 probable issues are a bacterial infection by
Pseudomonas syringae or a fungal infection by a fungus in the Pseudocercospora. It is very difficult if not impossible to differentiate the two without a diagnostic examination. You can bring a sample of your lilac to the Boulder County Extension Office on Tuesdays and Fridays from 9 to noon. Bring in a several complete branches and pictures of all three plants as well as a sample from a plant that is not infected.
After you take these samples, it is important to cut back all dead and diseased tissue and dispose of it in the trash. Do not compost. After diagnosis you will be advised about other treatments that will help.
Lilac Bacterial Blight | Horticulture and Home Pest News (iastate.edu)
Lilac Pseudocercospora Leaf Spot | Horticulture and Home Pest News (iastate.edu)
What's wrong with my lilac? Summer foliar diseases on lilac | Illinois Extension | UIUC
Thank you for your quick response! I will go into Boulder Extension tomorrow. Aleta
Sent using the mobile mail app
On 8/24/23 at 10:33 AM, Ask Extension wrote:
Sent using the mobile mail app
On 8/24/23 at 10:33 AM, Ask Extension wrote:
From: "Ask Extension" <<personal data hidden>>
Date: August 24, 2023
To: "Aleta Sherman" <<personal data hidden>>
Cc:
Subject: Re: Yellow Lilac Leaves (#0117022)
Date: August 24, 2023
To: "Aleta Sherman" <<personal data hidden>>
Cc:
Subject: Re: Yellow Lilac Leaves (#0117022)
