Hello!
We planted a few mums (my first garden project) last fall. They did well but then when the frost came didn't look very well. Left them over the winter and now that it is warming up (I live in Charleston, SC) they are blooming! No flowers yet, but I have been reading that I need to pinch them back. If I'd like flowers now is it okay to wait until they bloom and trim one by one in a process? I'd like the flowers to remain through the fall. Thank you in advance!

In late winter or early spring, when you see new growth, cut back all the old stems from last year to make room for new.

I wouldn't do any pinching now as you would be throwing away your future flowers but if you can sort out the old stems, cut them out. I never remember to pinch back my Mums and they do bloom all summer (the taller varieties fall over though).