The simple answer: In most cases, cut at the base of the spike with a sharp, clean tool. Of all of the more commonly available orchids, only phalaenopsis -- the moth orchid -- will rebloom from its old spike. When most orchids have finished blooming, the spike should be cut off with a sharp and clean blade as close to the base of the spike as is practical. Phalaenopsis will generally rebloom given a little extra care. The spike should be cut between the scar where the first flower was and the last node on the stem. One of the lower nodes will then initiate and generally produce flowers within eight to 12 weeks. Younger or weaker plants may not rebloom. It is also a good idea to cut the spike off entirely by midsummer to allow the plant to grow for next year’s bloom.