Answer: Some orchids should be repotted every year. Others may be happy in the same pot for seven or more years. As a general rule, don?t repot your orchid unless necessary. Orchids resent being disturbed. Repot if the growing medium has started to break down enough to reduce aeration; if the roots are creeping out well beyond the pot; or if new growth has unbalanced the plant.
An excellent book for you to read is Taylor's Guide to Orchids by Judy White. It's a complete guide containing cultural information and it goes well beyond what's in most beginner books, yet it is accessible and easy to understand. It has photos of different types of potting media, pests, and other culture-related materials and covers a satisfying mix of genera, both species and hybrids. These are followed by descriptions and cultivation tips to inspire you to grow some of the orchids depicted.
Your library probably has dozens of orchid growing books, as well.
Best wishes with your orchids!
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