Experts and BHG readers answer.
Daylily rust (Puccinia hemerocallidis) was first discovered in Florida in 2000 and has rapidly spread north and west from there. Similar to other rust diseases, daylily rust produces bright yellow or orange spots with raised pustules. Eventually leaves turn yellow and dry up. The disease spreads among gardens from gardeners who share plants or from nurseries that fail to realize that their plants are infected. Spores can also spread through the air. If you suspect that your daylily plants are infected with rust, remove all infected foliage and bury the trimmings. Sterilize tools with 70 percent rubbing alcohol or a 10 percent bleach solution to prevent spread. Wash your hands, gardening gloves, and clothes afterward to prevent spread to the rest of the garden. There is no specific fungicide labeled for daylily rust. Some daylilies show good resistance to rust. The All-American Daylily Selection Council (www.daylilyresearch.org) tests for rust resistance on the top varieties it recommends.