I am growing some South Pacific Scarlet Canna Lilies from seed in our greenhouses at work and the first true leaf is progressively becoming covered in brownish yellow spots. We don't seem to have any thrips at the moment or other insect that might be causing this but I am wondering if it might be the Puccinia thaliae Canna rust. Anybody have any experience growing this Canna or encountering this rust? Thanks!
