Trim the spike after all the old flowers fade and fall off for all orchids. Trimming the spike before the flowers fade damages present blooms and future growth.
Cut healthy Phalaenopsis and Dendrobium spikes to 1 inch above the next unused growing bud. If possible, leave the last used bud on the spike to provide space for healing. The orchids may rebloom from the spike in the same season.
Cut Oncidium and Cymbidium orchid spikes to their base. These orchids produce one flush of blooms per spike, and must produce a new spike for repeat blooming.