Answer: What you describe sounds like the fungal disease called rust. Snapdragons are quite susceptible - especially at this time of year in the Pacific Northwest. Hollyhocks suffer the same fate. Rather than trying to treat the problem with fungicides, simply cut away the foliage of your snapdragons. If the winter weather is mild, new shoots will develop from the roots in spring and you'll have healthy new plants. Rust spores can splash onto other plants, so remove the foliage as soon as you notice the tell-tale spots on plant leaves, and you'll avoid the spread to adjacent plants.
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