Usually orchids should be repotted every 2-3 years, when they just start to push out new root growth. The size of the pot chosen can depend on the growth rate of the orchid, and the size of the clump and root mass. But for many orchids, choose a pot whose top diameter is about a third to a half of the height of the orchid plant. So, if you have a 10-inch tall orchid, a 4- or 5-inch pot would work well. An exception is Dendrobium; it can be 24 inches tall, but grows best in a 4-5-inch pot.

You can use plastic or terracotta (clay) to repot your orchid. Clay lasts for many years and can be used over and over. A benefit of using clay pots is that the clay dries out the medium faster, which may help avoid rot in the inner root system. Clay pots also pull mineral salts out of the mixture, leaving fertilizer salt residue on the outer surface of the pot, away from orchids' sensitive roots. Clay pots help in measuring moisture levels as well. If the pot feels damp, it's not time to water yet. It's important not to over-pot, as all orchids, even terrestrials, need oxygen around their roots (clay pots help here), and smaller pots have more external surface area, where air can be exchanged, relative to interior space. Because too large-pots can result in the inner core of roots rotting, it is better to under-pot than to over-pot.

You can find more information in our guide Potting and Dividing Orchids. And you can find re-potting information specific to the orchid you are growing in our Orchid Care Guides.

For tips on a variety of gardening topics, see our Plant Information Guides.
- Courtesy of NYBG Plant Information Service