Powdery mildew how to handle - Ask Extension
I am having several issues with my bushes. Yesterday I was in my front yard trimming my Euonymus Gaiety and found crown gall. Then I was in my back ya...
Knowledgebase
Powdery mildew how to handle #797500
Asked June 23, 2022, 4:56 PM EDT
I am having several issues with my bushes. Yesterday I was in my front yard trimming my Euonymus Gaiety and found crown gall. Then I was in my back yard and found powdery mildew on all of my azalea bushes. I have 5 euonymus gaiety and at least 20 large 20 year old azalea bushes. I am sick about it. I tried apple cider vinegar with water, but I'm not sure that will work. I have a dog and don't want anything toxic. How can I treat this, or do I have to remove everything? If I leave it how long until they die? I am just sick about this, any help would be greatly appreciated. We have lived here 37 years and have never had any issues.
Howard County Maryland
Expert Response
Hang in there. All hope is not lost.
While we can't tell the extent of your troubles from 3 close up photos, we do have an idea as to what is going on.
First off, we don't see any signs of powdery mildew on your plants. We do see what looks like a type of scale insect on the wood of your azalea, and what may be lacebug damage (whitish fading) on the two leaves in your third photo.
Both of these insects are sucking insects. The puffy white blobs are scale, covered with a waxy coating. You should flip one over- it looks like it is full of eggs getting ready to hatch into tiny crawlers. If you can get out there soon with gloves and a stiff brush, try to dislodge (gently) and squish as many as you can find.
While you are there, look under any leaves that look spotty, faded, yellowish white for signs of lace bugs, most notable are black fecal dots on the underside of the leaf.
Keep watch too for ladybugs and other beneficial insects that help keep these pests in check (particularly if you don't generally use pesticides in your yard.
This page can be explored for more information:
https://extension.umd.edu/resource/azaleas-and-rhododendrons-identify-and-manage-problems
Start by doing this... if more is needed next season, there are insecticidal soap or horticultural oil options that would be safe for your dog. (We don't recommend vinegar applications.)
As far as your Euonymus goes, you can try to prune out any crown gall that you find and get them into the trash. It is a lovely plant but over the years Euonymus fortunei like yours, and Euonymus alata (Burning Bush) have been found to escape gardens and become very invasive, problematic plants that are displacing our native species. So much so that the Gaiety type is listed as a Tier I invasive species by the Maryland Department of Agriculture and is no longer allowed to be sold in Maryland. If you can't get control of the crown gall, enjoy the plant for as long as you have it but it will need to be replaced with something else.
Given the age of your landscape, there is likely more shade than there used to be so you may have areas where grass doesn't grow well anymore or would like more areas to sit in the shade and relax. This page from our website is great for thinking about how you might make your landscape more attractive and environmentally sound in the future:
https://extension.umd.edu/resource/lawn-alternatives
Christine
While we can't tell the extent of your troubles from 3 close up photos, we do have an idea as to what is going on.
First off, we don't see any signs of powdery mildew on your plants. We do see what looks like a type of scale insect on the wood of your azalea, and what may be lacebug damage (whitish fading) on the two leaves in your third photo.
Both of these insects are sucking insects. The puffy white blobs are scale, covered with a waxy coating. You should flip one over- it looks like it is full of eggs getting ready to hatch into tiny crawlers. If you can get out there soon with gloves and a stiff brush, try to dislodge (gently) and squish as many as you can find.
While you are there, look under any leaves that look spotty, faded, yellowish white for signs of lace bugs, most notable are black fecal dots on the underside of the leaf.
Keep watch too for ladybugs and other beneficial insects that help keep these pests in check (particularly if you don't generally use pesticides in your yard.
This page can be explored for more information:
https://extension.umd.edu/resource/azaleas-and-rhododendrons-identify-and-manage-problems
Start by doing this... if more is needed next season, there are insecticidal soap or horticultural oil options that would be safe for your dog. (We don't recommend vinegar applications.)
As far as your Euonymus goes, you can try to prune out any crown gall that you find and get them into the trash. It is a lovely plant but over the years Euonymus fortunei like yours, and Euonymus alata (Burning Bush) have been found to escape gardens and become very invasive, problematic plants that are displacing our native species. So much so that the Gaiety type is listed as a Tier I invasive species by the Maryland Department of Agriculture and is no longer allowed to be sold in Maryland. If you can't get control of the crown gall, enjoy the plant for as long as you have it but it will need to be replaced with something else.
Given the age of your landscape, there is likely more shade than there used to be so you may have areas where grass doesn't grow well anymore or would like more areas to sit in the shade and relax. This page from our website is great for thinking about how you might make your landscape more attractive and environmentally sound in the future:
https://extension.umd.edu/resource/lawn-alternatives
Christine
Thank you so very much for your help!!! I so appreciate you taking the time to help me! I am very excited I can control the azalea issue. I appreciate all the details!
Thank you,
Abby
On Jun 24, 2022, at 1:20 PM, Ask Extension <<personal data hidden>> wrote:
You are welcome.
Good luck!
Good luck!
