Hydrangea Cane Borer - Ask Extension
Hello. I recently discovered our 12 to 14 year old Nikko Blue hydrangea has a serious cane borer problem. I've tried cutting back the canes to below w...
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Hydrangea Cane Borer #718469
Asked August 28, 2020, 10:04 AM EDT
Hello. I recently discovered our 12 to 14 year old Nikko Blue hydrangea has a serious cane borer problem. I've tried cutting back the canes to below where they are hollowed out, but some go as far as the base of the plant. Is there any way to save this plant, or should we remove it. There are several 1 to 2 year old hydrangeas nearby that have been affected, too, but I've been able to cut and seal the canes on these plants below the affected area.
Lucas County Ohio
Expert Response
Hi There Lucas County
By cutting back the canes to below the hollow you are doing exactly the right thing. Do not compost the discards.
Since your hydrangea is established there should be enough energy in the plant to put out new growth now so that it will be vigorous enough to withstand winter.
You may have to do this over several seasons. Borers often attack plants that are stressed. As your hydrangea become more vigorous the insects will look for other victims (hopefully not yours). You are on the right path. Best of luck to you.
By cutting back the canes to below the hollow you are doing exactly the right thing. Do not compost the discards.
Since your hydrangea is established there should be enough energy in the plant to put out new growth now so that it will be vigorous enough to withstand winter.
You may have to do this over several seasons. Borers often attack plants that are stressed. As your hydrangea become more vigorous the insects will look for other victims (hopefully not yours). You are on the right path. Best of luck to you.
