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Hollyhock rust

Symptoms

Orange-brown spots on foliage and stems. Leaves may die and drop from plants, weakening the plant and resulting in death in extreme cases.
Find it on: hollyhocks, mallow
Time to act: all year round

Overview

Rust fungus is the curse of hollyhocks. The undersides of the leaves are often peppered with bright yellow or orange-red rust spots with corresponding beige-yellow splodges on the upper surface. Eventually, it affects the whole plant, with leaves starting to fall away from the base. In severe cases the stem becomes infected too, and the whole plant may die.
Solution
Orange-brown spots on foliage and stems. Leaves may die and drop from plants, weakening the plant and resulting in death in extreme cases.
Organic
Remove infected leaves from plants as soon as the fungus is seen. In winter, when the hollyhock dies down, clear away any infected leaves as they will harbour the fungal infection. Weeds such as common mallow, which are related to hollyhocks, also harbour rust so pull them out if they appear in the garden.
Chemical
Every two weeks from early spring onwards spray plants with a systemic action fungicide.



Discuss this problem

Talkback: Hollyhock rust
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meadoradelfine 24/11/2011 at 15:29

My hollyhocks have had rust for 3 years now. I've always put it doiwn to the same rust as my apple tree and hawthorn hedge suffer with.Obviously not! I pulled all the infected leaves from the hollyhocks and burnt them. As soon as I saw the leaves starting with rust I removed the the infected ones and sprayed each p[lant thoroughly with a specific fungus killer.
Even the self seeded youngsters have the rust...so have been sprayed as well... and all will be sprayed regularly.
Fingers crossed!

gordonthegarden 24/11/2011 at 15:29

Excellent answers to my problem, as I have a big problem with rust on the hollyhocks. However there is no mention if Systemic Fungicide spraying will harm the bees. I have read the lables on various products and no mention what so ever if it will effect the bees in anyway.

junerose43 24/11/2011 at 15:29

have also rust on my hollyhocks, have removed many leaves and they are flowering now, would prefer not to spray, would mulching the soil beneath help? if so which mulch works best?

MelB 24/11/2011 at 15:29

Great - brief and clear. My first-ever double hollyhocks are flowering beautifully but the infection is spreading fast. I think I'd better remove, destroy and fungicide spray as well, I'm afraid. And thanks Meadoradelfine for warning to monitor new self-seeded plants too.

Ele Brown 15/01/2012 at 12:55

Last year I read on a gardener's forum to spread corn meal around the hollyhock in the winter/spring. I was dubious but thought I had nothing to lose so I did that and no rust lasy year! You need to use corn meal not corn flour. I found it in a continental shop.

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