University of Maryland Extension: Garden Q&A
Q: My day lilies look so ratty this time of year! Can I cut them down and be done with them?
A: Around mid-August you can try “dead-leafing,” which entails wrapping your hands around clumps of dead leaves and yanking them out. Or, you can simply cut them down to a few inches from the ground with shears. They’ll put our some new growth which won’t get as tall as the early season leaves, but should look good and stay green until frost.
Q: I water my grass six days a week for 45 minutes with an irrigation system, and it still has brown spots. I’ve been told that when lawn is brown, I should water. What more can I do?
A: Stop watering!
Tall fescue lawns get very few problems, but brown patch fungus is one. What conditions encourage brown patch? High humidity and high temperatures. By watering so much, you are artificially creating a high humidity/moisture environment, perfect for spread of this fungus.
The good news is that brown patch kills blades but rarely grass roots. Leave your lawn alone and it may recover on its own. If some areas are dead, overseed in early fall.