Snap off the seed pods that form from the bloomed out daylilies unless you want them to do to seed. They do not come true from seed so you do not want the seeds to drop in your daylily beds. But if you want to see what might come of your seeds then plant them out in a separate seedling bed or start them indoors to transplant out later.

Five feet is pretty high for most varieties of daylily scapes and flowers. You sure they are that high?

Hm...when you say "they don't come true" are you talking about fancy hybrids that might reproduce something different? Or do you just mean the new seedlings won't be healthy?

The tall daylilies are the orange kind that grow along the road...I guess they are the 'natives'? They kind of grow wild so I imagine they would re-seed themselves?

I wouldn't mind if all my perennials re-seeded and filled up all the space... it's a hard climb to take bare earth and try to fill it up. All of it was lawn until last april.

Ah. You have the old fashioned ditch lilies. I don't think they make seed pods. I mean the seeds are not repoductions of the parents and could look like anything. Pretty or ugly or anything in between.

The ditch lilies are actually from Asia, and have naturalized here. They are triploids and do not make seed, but aggressively spread by vegetative means; like stolons or rhizomes. Provide rich loose soil for them to grow in and soon you will have more than you need.
After the bloom dries up, it is not necessary to pull it off, but if it pleases you, it doesn't hurt anything. Dead heading will not give you more bloom. Good luck, Ed

As far as day lily reproduction... I think I planted about 2 Stella d'oro plants last year... This year they have gone nuts, there must be about 10 of them!!!!

Stella does spread fast, and she makes seed, lots of it all by herself, or maybe with the help of insect friends. Look for seedpods and when they start to turn brown and crack open, harvest them. Then you can decide if you want to start growing hybrid daylilies. Good seed is usually small shiny and black, firm to a gentle squeeze. Store in a cool dry place till ready to plant. And btw, plants making seed will make less bloom.
Ed