If you are talking about Phalaenopsis orchids, yes. I like to cut it higher, just under where the first flower formed on the spike, while Spritzhenry likes to cut lower, just above the first scale-like leaf on the spike. Other kinds of orchids should have old flower spikes cut off, but they will not form new spikes from the old like Phalaenopsis will. If you are talking about cutting the bamboo-like pseudobulbs of Dendrobium orchids, I wouldn't, except to remove old, shriveled pseudobulbs.