Hollyhock leaf issue - Ask Extension
Do you know what might be the issue with this hollyhock leaf? See picture. Remedies including preventing this next year?
Thanks!
Ron
Knowledgebase
Hollyhock leaf issue #766052
Asked August 06, 2021, 10:44 AM EDT
Do you know what might be the issue with this hollyhock leaf? See picture. Remedies including preventing this next year?
Thanks!
Ron
St. Louis County Minnesota
Expert Response
Hello, happy to help.
This appears to be hollyhock rust, a fungal disease. It can come in on the wind but by practicing good plant hygiene, you can certainly get it under control. These control measures include removing and destroying affected leaves as soon as the rust appears and removing any mallow plants in your garden since they are also affected by the rust and can provide spores that can take the wind toward your hollyhocks. The best disposal methods are either by burying the affected material or burning it.
Avoid planting them close together because a close environment fosters the development of the fungi. Water at the ground level (no sprinklers) and early in the day to allow the sun to dry any wet leaves if that happens. Finally, be sure to remove and destroy all hollyhock debris in the fall once they decline starting this year.
Good-luck!
This appears to be hollyhock rust, a fungal disease. It can come in on the wind but by practicing good plant hygiene, you can certainly get it under control. These control measures include removing and destroying affected leaves as soon as the rust appears and removing any mallow plants in your garden since they are also affected by the rust and can provide spores that can take the wind toward your hollyhocks. The best disposal methods are either by burying the affected material or burning it.
Avoid planting them close together because a close environment fosters the development of the fungi. Water at the ground level (no sprinklers) and early in the day to allow the sun to dry any wet leaves if that happens. Finally, be sure to remove and destroy all hollyhock debris in the fall once they decline starting this year.
Good-luck!
Thanks! If most of the leaves on a plant have rust, is it best to sacrifice the plant?
Ron
Hello Ron,
Since the literature says not to use seeds from infected plants, I have to believe that the plant will continue to have the problem next year. So, yes, probably sacrifice it.
The literature also recommends buying resistant varieties so check with your nursery for those varieties if you want to try again next year.
Be sure to destroy all material that you pull out.
Good-luck!
Since the literature says not to use seeds from infected plants, I have to believe that the plant will continue to have the problem next year. So, yes, probably sacrifice it.
The literature also recommends buying resistant varieties so check with your nursery for those varieties if you want to try again next year.
Be sure to destroy all material that you pull out.
Good-luck!
Thank you for your help!
