Peony Pests and Shrub rose issue - Ask Extension
Hello,
I have two issues in my garden this year:
1) I have a white peony plant that I have had for many years and this year I noticed that when ...
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Peony Pests and Shrub rose issue #834692
Asked June 09, 2023, 9:56 AM EDT
Hello,
I have two issues in my garden this year:
1) I have a white peony plant that I have had for many years and this year I noticed that when the buds started to open, they quickly browned and died. Upon close inspection I see very small bugs, almost microscopic. I have attached two photos.
2) I have a very old shrub rose that for the past few years, when the buds appear, the quickly shrivel and die. This year I put a rose fertilizer before buds appeared and the first few opened up beautifully, but unfortunately all the subsequent blooms (there are many), didn't open and quickly shrived. (Photo attached) It looks to me like this bush might have some sort of fungus.
I do not want to use any insecticides in my yard. Yesterday when I asked an "expert" at Bachmans, I was told to use Rose Rx 3in 1 that is "certified for organic gardening" and that it isn't harmful to people or pets. They said this product would take care of both problems. Upon reading the insert, it says the product is toxic to bees and sounds pretty toxic to humans as far as I'm concerned. My questions to you are:
1) Should I dead head both the peony and rose blooms completely?
2) Is there a natural remedy, such as peppermint oil, that can be used to treat these plants?
3) I have another peony bush on the other side of the yard, but it doesn't look like it has been infected as of yet. Should I treat that one prophetically?
Thank you in advance for any and all of your help!
Regards,
Madeleine Hart
Ramsey County Minnesota
Expert Response
The good news is the diagnosis is straight forward in both cases: thrips damage.
The bad news is these tiny but destructive insects are difficult to control.
Information in the following publication explains why:
https://content.ces.ncsu.edu/flower-thrips
Deadheading buds and blossoms that seem to be affected is recommended.
Rose Rx 3in 1 is a multi-purpose product--fungicide, insecticide and miticide, a tall order for the sole active ingredient: neem oil.
Go here to learn more about neem oil:
https://extension.unh.edu/blog/2020/01/what-should-neem-be-used-plants
Although some beneficial insects might protest the designation, neem oil is considered a "soft" insecticide certified organic by the Soil Association and COSMOS.
Spinosad, another soft insecticide, also boasts organic credentials. It's labeled for use against thrips. Go here to learn more:
https://ipm.cahnr.uconn.edu/spinosad-the-first-selective-broad-spectrum-insecticide/
The bad news is these tiny but destructive insects are difficult to control.
Information in the following publication explains why:
https://content.ces.ncsu.edu/flower-thrips
Deadheading buds and blossoms that seem to be affected is recommended.
Rose Rx 3in 1 is a multi-purpose product--fungicide, insecticide and miticide, a tall order for the sole active ingredient: neem oil.
Go here to learn more about neem oil:
https://extension.unh.edu/blog/2020/01/what-should-neem-be-used-plants
Although some beneficial insects might protest the designation, neem oil is considered a "soft" insecticide certified organic by the Soil Association and COSMOS.
Spinosad, another soft insecticide, also boasts organic credentials. It's labeled for use against thrips. Go here to learn more:
https://ipm.cahnr.uconn.edu/spinosad-the-first-selective-broad-spectrum-insecticide/
Thank you so much for your prompt reply and for sharing your expertise. I greatly appreciate it!
I’ve dead-headed everything and will attempt to treat my plants!
Gratefully,
Madeleine Hart
On Jun 9, 2023, at 11:05 AM, Ask Extension <<personal data hidden>> wrote: