Q: I have a patch of daylilies, and most of the leaves have turned brown. I've been pulling them off and now the space is mostly bare where the plants used to be. I'm not sure what I should do now. They've left a lot of open space.
A: That's a common occurrence with daylilies. Many of them get a disease called leaf streak soon after they're done blooming.
Small rust-colored streaks enlarge, coalesce and eventually cause whole blades to brown out. When that happens, all you can do is pick them off. They're not doing the plant any good anyway.
If the disease is bad enough, go ahead and cut the whole plant to a stub. Daylilies are tough enough that they usually grow through this disease and produce fresh foliage within weeks. Come late summer and fall, the plants usually look pretty good again and usually don't get re-infected.
However, once your plants have this disease, they typically get it year after year to varying degrees (depending on weather). I just pick off the brown and get the infected foliage out of the garden and basically accept it as part of daylily care.
The other option is to begin spraying your plants with a fungicide every spring and to repeat every 7 to 10 days through summer. You could also start spraying at the first sign of streaking, but if you wait too long, even fungicides won't help a disease that's running full steam.
Dividing your plants every two or three years can also help reduce the severity of this fungal disease.