Question
Hi! Recently I bought some discounted orchids at my local hardware store. I bought two phalanopsis orchids, one oncidium , and one cattleya. They had very healthy leaves except they had finished blooming and all they had was an empty flower stalk. I was wondering what I could do to get my orchids to rebloom. Do I need to fertilize or change their growing conditions?

Answer
Victor, yes, they can all rebloom. However, they will need special care to ensure they grow healthy, new tissue.  In general, if cared for properly, they will rebloom annually-- generally in the spring.  First, each plant must be repotted in fresh fir-bark based orchid potting mix.  Choose a commercially marketed brand of orchid potting mix.  Strain out the smaller dust-like particles and soak the remaining larger particles for an hour.  Then remove each plant from its pot, wash off the roots before repotting.  Remove any roots that are stringy, or mushy.  In repotting, place  the plant with its good roots into a pot that is well drained. Then add the fresh potting mix you prepared.

Growing requirements differ with oncidiums and cattleyas from those of phalaenopsis. The former require brighter light than the latter.  Only water when there is new growth.  Do not keep the repotted plants too wet and do not let then sit in water.