Caring for an orchid
Do I trim back the stem once the flowers have fallen off?
Only trim off any brown or dead growth. That stem will flower again if you leave it. In fact, this saves the plant quite a bit of energy. They will be a little healthier if you leave them. Here is an article that will help: https://www.gardeningknowhow.com/ornamental/flowers/orchids/how-to-prune-an-orchid.htm