You can cut before they're completely dry--I cut them with a good amount of stem attached to the head and hang them upside-down in my attic. A handful of stems is held together with a rubberband and the band put on a nail in the rafters, as the stems dry they do shrink in diameter so the tension of the rubberband keeps them all bundled tightly.

Hanging works fine to dry the heads and usually they do not drop their seeds unless they're disturbed. Play it safe and lay a sheet under the celosia to catch any seeds that do fall. I fold the sheet in foutrhs instead of laying out the entire size sheet--fourths is big enough.

T

Thanks! I see no signs of drying yet. Everything still looks like it's blooming. Do they change color when they are starting to dry?