Orchids generally should be repotted about every one to two years. Doing so provides a good opportunity to inspect them carefully, clean them up and transfer them to new pots with fresh potting mix. However, you may want to repot them outside their regular potting times for several reasons. Here are six common ones.
The Orchid Is New
It’s always a good idea to repot a new orchid. Often, orchids have been sitting for a long time before being purchased – possibly for a year or more. In that time, they may have outgrown their pot, or they may have been overwatered and the potting medium has started to decompose. There may not even be any medium at all (just sphagnum moss), or the medium is the wrong type for the orchid. They might have picked up a bug or two, maybe a fungal disease. The orchid could also be potted in the wrong kind of pot, or a pot without any holes, or even a pot that’s cracked.
Soon after you take the orchid home, look it over. Check to see that the potting medium is still good. Take it out of the pot, check the roots and potting medium, look for signs of disease or insects, and examine the plant closely for any other problems. If it doesn’t require re-potting right away, you can wait until it’s finished blooming.
The Potting Medium Needs to Be Replaced
Orchids are aerial plants, meaning they grow with their roots exposed to air. They grow on trees where their roots can get ample rainwater, but are able to dry out between showers. For convenience, they’re potted up and grown in a bark medium. The bark pieces are large enough for water to flow freely through, wetting the roots, but also allow air to circulate. As the bark ages, it breaks down into smaller and smaller pieces. Eventually it begins to compact and air can’t get to the roots anymore. It may begin to hold water, becoming soggy, and cause the roots to rot. Or, it becomes so compact and dry that it won’t let water through to the roots. In either case, the roots are in trouble.
If the plant is new, the potting medium should be changed as soon as possible. For older plants, replace the potting medium on a regular basis. Once a year is probably enough.
Pots Are Not All the Same
Orchid pots are made of all kinds of materials – clay, plastic, ceramic, bark boards, woven plastic, and fiber. The pot may be made of the wrong material when you buy it. The holes could be plugged up or have no holes at all. It could be broken or be too small for the orchid. The best kind of pot is going to be the one that drains well, doesn’t retain too much moisture and allows air to get to the roots.
Many orchid growers like clear plastic. You can easily see the roots and the condition of the growing medium, and whether it’s wet or dry (a good thing if you’re trying to decide if you should water it or not). My personal preference for orchids is clay. Clay pots are shallow, heavy, and have slits in the sides and a hole in the bottom for drainage. The clay is porous, and allows air to pass into the potting medium and water to pass out and evaporate. Its weight can keep top heavy plants from falling over.
The pot shouldn’t be too large either. A pot that is too large may stay wet longer, leading to root rot.
Orchid Is Overgrown
Orchids like it a little crowded in the pot, but not too much. They do best when the volume of roots and potting medium is about the same. In a smaller pot, the medium will dry out quicker, and you’ll avoid root problems. Eventually the roots run out of room, though, and when they do, they’ll start to grow around the inside of the pot, as well as out the holes. Those roots will eventually form a knotted tangle and push the plant up out of the pot. Orchids generally outgrow their pots in six months to two years, and need to be repotted.
Diseases or Pests
Orchids are bothered by a variety of pests and diseases. They can be brought in with new plants from a nursery or supermarket, or find their way into your home or greenhouse from outside. Sometimes, tiny snails get into the pot and feed on new growth. Most bugs are harmless, but you still don’t want them crawling around the house.
Some Other Things to Keep in Mind
Although there may be a specific reason your orchid should be repotted, like those mentioned above some general guidelines will help.
Spring is the best time to look over your orchids and assess their needs.
They should be repotted every one to two years,
Orchids should be repotted while they’re in active growth.
Monopodial orchids, like Moth Orchids (Phaleanopsis), grow upward from a single point, and Sympodial orchids, like Cattleyas, grow outward horizontally, arising from growth points along rhizomes. Each have some idiosyncrasies you should consider when deciding whether to repot them or not.
Phaleanopsis put on one to two new leaves a year, losing about the same while they grow upward. As they do, they become leggy and top heavy, the stem leaning to one side. Roots emerging along the growing stem become aerial. They should be repotted every two years to keep them healthy and attractive.
Cattleyas produce one flush of root growth with each new plant they produce. Some varieties send out new roots just before they bloom, others just after. They should be repotted while the new roots are emerging. Inspecting your plants frequently and getting to know their