Hollyhock: Rust
categories: Flowers Hollyhock Hollyhock Diseases Ornamentals
last review date: 2025-07-28 05:19
Photo by: R.S. Byther
Biology
Hollyhock rust is caused by a fungus that overwinters in basal leaves which may live through the winter, or on plant debris. Spores remain viable for at least four months in the soil.
Reddish raised spots develop on leaf undersides and then darken late in the growing season. Stems may also be attacked, and if the case is severe, leaves may dry up and hang down.
Management Options
See "Using Integrated Pest Management (IPM) in the Landscape" for successful problem management techniques.
Non-chemical Management
Select non-chemical management options as your first choice!
- Pick up and burn all infected plant parts during the growing season, at the end of the growing season, and again in early spring.
- Remove other hosts like cheeseweed (Malva parviflora), Lavatera, Hibiscus, and other Malvaceae plants.
Chemical Management
IMPORTANT: Visit Home and Garden Fact Sheets for more information on using pesticides.
- Fungicide applications should only be used in conjunction with cultural management options.
Approved Pesticides
Examples of pesticides that are legal for home use in Washington State are listed below.
The list may not include all products registered for this use.
Additional Image
Photo by: R.S. Byther
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