Orchids produce unusual colorful flowers on long stems and are often grown as houseplants. They require repotting when the root system becomes crowded. Waiting too long to repot an orchid plant increases the chance of root damage during the repotting process. However, repotting too often, or incorrectly, may cause needless transplant shock that delays or prevents bloom production.
Commercial orchid potting mixes are widely available that contain different types of bark and mosses. It is best if you use a potting mix similar to the one from which the orchid is removed. If you want to change the mix completely, pot in a mixture of 1/2 new mix and 1/2 old style mix so the orchid can become adapted to the change.
Repot orchids when there is new growth and the roots have not yet filled the pot. New growth usually appears after a bloom period. A rule of thumb: Phalaenopsis, Miltonia, Dendrobium and Paphiopedilum orchids are usually repotted annually; Oncidium, Odontoglossum and Cattleya orchids are repotted every other year; Cymbidium and Vanda orchids are repotted every third year.
Any container can be used for orchids, such as glass, plastic or terracotta. Terracotta dries out faster than other containers, so you’ll need to add water more often. Remember when choosing a container that it must have drainage holes so water does not sit and cause the orchid’s roots to rot. The best type of container is a clear plastic pot that allows you to see if the roots are dry and if the roots are outgrowing the pot.
Choosing a container that is too large causes the orchid to spend its energy creating new roots to fill the pot rather than creating new top growth. If the pot is too small, the roots remain crowded and are susceptible to rot and mildew. Choose a container that comfortably accommodates the roots while leaving 1 to 2 inches of space around the root section, so the root section is slightly tight in the pot.
New potting mix should be rinsed well before it’s used for potting an orchid. Rinsing the medium removes small particles that wash from the bottom of the pot and prevents transplant shock.
Use a pair of scissors, or sharp knife, sterilized with rubbing alcohol to trim off any dead or dying roots visible once the orchid is removed from the original pot. Sprinkling powdered cinnamon on the wounds prevents disease, as powdered cinnamon acts as a natural fungicide.