"Seriously?" OK, this issue doesn't rank up there with global bank failures - unless you're the owner of a garden full of daylily plants.
Obsessive gardeners (are there other kinds?) simply cannot walk outside in the summer without bending to pull a weed, pinch off a dead flower, or defeat a bad insect.
"Sittin' Here In Limbo": This is true in their own garden and it's sometimes true in every private garden, city scape or public garden they visit. Who doesn't appreciate a little help - right? Weeeelllll - not always so right.
"Pig's Boogie": Let's put this in perspective: Do you reach over with your finger and pick spinach out from between your friend's front teeth? Really? You don't do it because it would be terribly impolite and invade their personal space and eeewww anyway.
"Think": It's a little like that with deadheading without permission. Here's the rationale:
"The Thrill Is Gone": Hybridizing daylilies requires the seed pods be allowed to develop. A well-meant deadheading will stop the seed heads from developing and end an opportunity to develop a new daylily. And I might add, end a friendship.
"Shady Grove": Deadheading another person's daylilies (or any other flower) insinuates, by that very action, another gardener isn't quite up to snuff - at least up to your standards.
"Wayfaring Stranger": Deadheading another person's garden is like finding fault with a child's painting because they didn't stay in the lines. It's their creative process that you are inferring is somewhat lacking because it doesn't meet your own high standards.
"There Ain't No Bugs On Me": Some well-meant folks feel if they "show" others how to do things right - the other person will be grateful. I've never seen anyone grateful of unsolicated advice. Discuss with them if you must and offering might be fine. If you discuss and offer and the result is "no", then take it with good grace and find something else to do.
"Up From The Desert": I've had daylily friends prefer a certain method to their deadheading. That method is important to them and their gardening: In a bag, on the ground, between rows, in the a.m., at dusk, or compost.
"Nine Pound Hammer": The issue of public gardens is one of risking getting kicked out or worse. It's not your land and you can be charged if they so choose. Granted they may be happy for the help - the trick is to ask first.
"One Kind of Favor": The issue of city maintained gardens and pots is a little more loose. Most are hurting for volunteers to help. I would still call to offer help.
"Knockin' On Heaven's Door": The deal is if you can't resist the urge to help others - call and ask to help FIRST. (Freedom House, the women and children's domestic abuse shelter, lost their garden volunteers this summer. Let me know if you'd like to help them.)
More on dead heading daylilies: Freakin' At The Freakers' Ball - Article #179.
"American Popsicle": If your allergies are making your sinus hurt around your nose and eyes, eat frozen fruit. I freeze on a cookie sheet: individual grapes, blueberries, strawberries, slided peaches & pineapple. Put in the feezer in ziplock bags. A few in a bowl and the cold apparently makes the swelling go down. It doesn't take much, good nutrients and low calorie.
Daylilies photos - top to bottom: Lunar Max, Night Beacon, and Chicago Star. J.G. photo from open net pages.