Japanese lilac tree leaves turning brown - Ask Extension
Our Japanese lilac tree leaves are turning brown and dropping off.
We are uncertain what is causing this. Same thing happened a few years ago and le...
Knowledgebase
Japanese lilac tree leaves turning brown #799863
Asked July 07, 2022, 1:21 PM EDT
Our Japanese lilac tree leaves are turning brown and dropping off.
We are uncertain what is causing this. Same thing happened a few years ago and leaves have never returned to those branches.
Hennepin County Minnesota
Expert Response
Thank you for writing.
I cannot tell from a distance but my guess would be lilac scale.
https://www.ortho.com/en-us/problems-and-solutions/scales-lilac
https://pnwhandbooks.org/insect/hort/landscape/hosts-pests-landscape-plants/lilac-syringa-oystershell-scale
or lilac blight
https://extension.oregonstate.edu/news/how-recognize-treat-avoid-lilac-bacterial-blight
The treatments are different so you must make a diagnosis.
Cut down a branch that is not completely dead and send me two close photos, one of the leafs and twigs and another of some small branches
I cannot tell from a distance but my guess would be lilac scale.
https://www.ortho.com/en-us/problems-and-solutions/scales-lilac
https://pnwhandbooks.org/insect/hort/landscape/hosts-pests-landscape-plants/lilac-syringa-oystershell-scale
or lilac blight
https://extension.oregonstate.edu/news/how-recognize-treat-avoid-lilac-bacterial-blight
The treatments are different so you must make a diagnosis.
Cut down a branch that is not completely dead and send me two close photos, one of the leafs and twigs and another of some small branches
Dear Steve
Thank you for getting back to me so quickly. Here are the photos you requested. If another photo is necessary, let me know.
Thank you again for your advice
Kathy severson
<personal data hidden>
Thank you for writing.
The picture of the stem is blurry but looks like Lilac Oystershell Scale.
I would start by cutting off generously the affected branches and putting them and fallen leaves and twigs in a bag. Then hose the plant with a nozzle at the jet setting. Then with your thumb nail gently rub some of these bumps to see if they are soft. Try misting with neem oil (NOT WITH PYRETHRIN, common is some Neem Oil products).
Inspect the plant a week later and send me a picture as you have done this time.
The picture of the stem is blurry but looks like Lilac Oystershell Scale.
I would start by cutting off generously the affected branches and putting them and fallen leaves and twigs in a bag. Then hose the plant with a nozzle at the jet setting. Then with your thumb nail gently rub some of these bumps to see if they are soft. Try misting with neem oil (NOT WITH PYRETHRIN, common is some Neem Oil products).
Inspect the plant a week later and send me a picture as you have done this time.
