After an orchid has finished flowering, cut the stem one inch above the base so that it can reserve its energy for new leaves and roots. Using a sterile blade to cut the stem prevents the spread of a virus or fungus.
Most Phalaenopsis orchids don't need cutting after flowering. They usually re-bloom on the same flower spike in eight to 12 weeks, but the new flowers are smaller. If cutting the stem is preferred, cut just above the first or second node, a method that promotes the growth of side shoots. Once the flower spike starts to turn brown, cut it at the base.