I never pinch my cosmos. I cut as long a stem as I need to, even if it means sacrificing the two side buds and a couple more below. Or I'll snip out the center flower if the side buds are ready. I try to cut cosmos when they're just starting to open. They don't last quite as long as some of the other flowers, but they sure are pretty in a bouquet.

Kelly

Thanks Kelly! It sure seems like a waste to sacrifice all those other buds. I'm gonna cut the center on a few and see if the side buds bloom at about the same time on some of them.

Steve

Steve - they'll keep blooming...just make sure you don't cut the entire plant! Sometimes you do sacrifice the sides or wait until the middle bud is open and the sides show color...they will open up in most conditions! I'm trying to remember if I pinched them last year or not...I'm thinking I did...but am drawing a blank at the moment!
Wendy

Mine usually get ahead of me from one cut to the next, so those get sacrificed.

I try to pick when only the first ring of pollen starts to show on the strongest flower. Or, will pick when the largest bud is colored and starting to crack but not open yet. These usually start to unfurl by the time they get to market. That makes them an additional day or so longer for the customer.