From my perspective, rooted here in the soil, the yellowing and spotting you see on my leaves is a clear sign of distress. It feels like an invasion. A common fungal pathogen known as *Puccinia malvacearum*, or hollyhock rust, has taken up residence. This fungus is an obligate parasite, meaning it needs me, its host, to survive and complete its life cycle. It doesn't want to kill me outright—that would be counterproductive—but it will weaken me significantly if left unchecked.
The cycle often begins in the spring or early summer when the weather is cool and my leaves are frequently wet from rain, dew, or overhead watering. The fungal spores, called urediniospores, are incredibly light and travel vast distances on the slightest breeze, or they hitch a ride on the hands and tools of gardeners. When these spores land on the moist surface of my leaves, they germinate. They send out tiny fungal tubes that directly penetrate my epidermis, breaching my primary defense and invading my living tissue.
Inside my leaf, the fungus begins to grow and steal the nutrients I work so hard to produce through photosynthesis. This theft directly causes the chlorosis, or yellowing, you observe. The areas around the infection sites lose their green chlorophyll because the fungus is diverting those resources for its own use. The raised brown spots are the fungal structures themselves, called pustules. These are my body's attempt to contain the infection by pushing it out to the surface, but in doing so, they rupture my epidermis, creating those characteristic spots and releasing millions of new spores to continue the cycle.
As the infection progresses, the damage becomes more severe. The numerous pustules disrupt my ability to breathe and perform photosynthesis efficiently. My leaves may begin to wither, curl, and die prematurely. This forces me to expend precious energy trying to produce new leaves instead of focusing on developing strong stems and abundant flowers. A severe rust infection can leave me stunted, with fewer blooms, and incredibly vulnerable to other stressors like drought, extreme heat, or additional diseases.
To help me fight this battle, I need you to be my ally. First, please practice excellent sanitation. Carefully remove and destroy all my infected leaves—do not compost them, as the spores can survive. In the fall, clear away all plant debris around my base to eliminate any spores overwintering there. When watering, please water my soil, not my leaves, to keep my foliage dry and create an less inviting environment for the fungus. Ensuring I have good air circulation around me by avoiding overcrowding will also help my leaves dry faster. For severe cases, you might consider applying an appropriate organic fungicide, like neem oil or a sulfur-based product, as a protective coat on my healthy leaves.
