Why Do You Need to Repot Orchids?

Orchids don’t need much care, but one thing they need sometimes is the occasional repotting. But why would orchids need to be repotted, and how do you do it?

Why would you need to repot an orchid? It may have come planted in an unsuitable medium, like a heavy, claggy soil. Besides that, organic mixes break down after two years or so, leading to rot, and lose their nutrients even if they don’t; slugs, snails and other pests also necessitate repotting. You can also repot your orchid for positive reasons, i.e. if it has grown large enough that it could thrive in a larger pot. Take the orchid from its pot, trim away rotten or dried roots, and swap out the potting mix for fresh.

The guide below first looks at the reasons why you might need to repot your orchid, and how long it will be before you have to. It will then look at what you need to repot an orchid, from any new pots it might benefit from to the special potting media you should consider using.

When Should You Repot Orchids?

Orchids prefer living in potting mix to living without it, at least within the confines of your home. As is the case with all plants, there are several reasons why you should repot your orchid occasionally. Reasons include:

  • The mix that the orchid came with is unsuitable. Repot immediately.
  • The mix is decomposing or rotting, affecting your orchid’s roots. Takes 1-2 years after the potting mix was first used.
  • The mix is old and has lost the nutrients it used to contain. Takes 1-2 years after the potting mix was first used.
  • Your orchid has grown larger, so could benefit from being put into a larger pot. Optional; depends on how quickly your orchid grows.

You could also choose not to bother repotting your orchids. You can still keep an orchid for a year, two years or even three years or longer without repotting it if it was potted in a suitable mix. But do be aware that if you choose this route, your orchids will have a much shorter lifespan than they would otherwise.

Unsuitable Orchid Mix in Store-Bought Orchids

I’ve bought lots and lots of orchids from grocery stores, and been given many more as gifts. Probably half of them have come with a mix that’s completely unsuitable for them: too thick, too claggy, not draining enough. It’s for this reason that I like to repot orchids when I get them home from a store (unless I buy them from a proper garden center, in which case they typically have a proper medium to live in).

Every time I’ve repotted one of these orchids, I’ve found their roots pale, if not starting to rot already. The mix will be packed in so tight around the base of the orchid’s stem that even the stem turns pale. These orchids invariably do better once I’ve repotted them, so it’s something you should definitely consider doing.

Orchid Mix Rotting & Decomposing

Even if you buy an orchid in a suitable organic medium, though, there will come a time when you need to repot it. That’s because all organic media from coco chips to soils and fir bark will eventually degrade, decompose and become unsuitable.

How long this takes depends on the medium you choose to use. I find it takes about two years for regular coconut bark to turn soft and start rotting. This won’t start in the mix at the top of the pot, because that’s not the mix that stays wet after you water it; rather, the mix at the bottom or in the middle of the pot will go first. This isn’t always easy to see, so you should check every once in a while to make sure it’s OK, or just repot every other year to be sure.

One problem with your orchid’s mix breaking down is that it holds onto more water. It will form claggy deposits around your orchid’s roots, keeping water in place, and causing the root to rot. At the same time, this stops the orchid’s roots from accessing air, which they need to do—and why the best orchid mixes allow lots of room, lots of gaps in the pot.

On top of that, the mix breaks down because of bacteria. These same bacteria will then also eat into and rot your orchid’s roots. Root rot will prove fatal if the rot reaches the orchid’s stem, i.e. its main body. This doesn’t apply to inorganic mixes like styrofoam or perlite, because these won’t rot; but everything else will break down eventually.

Orchid Mix Losing Nutrients

Even if the mix isn’t decomposing, though, it’s still best to replace it every once in a while. That’s because the mix can lose some of the minerals it contains through continual watering. The water can leach out some of the minerals in, say, coco bark; while these can be replaced to an extent by the minerals in orchid food, the long seasons that it’s best not to use orchids food will see the mix progressively lose its nutritional value. By repotting the orchid, you replace those minerals.

Again, this doesn’t apply to inorganic potting mixes like styrofoam or perlie. That’s because these materials don’t contain nutrients that orchids can access anyway.

Your Orchid Is Growing Bigger & Bigger

Orchids are living plants, and like all living plants, they’ll grow bigger if kept in a suitable environment. If your orchid receives all the water, all the food and all the sunlight that it needs, then it will reward you by growing bigger leaves and more roots. Eventually, it will get to the point where it would benefit from being kept in a larger pot. It can then become even bigger and even healthier.

This isn’t strictly necessary. If you leave your orchid in its pot, it will stay at the same size its entire life (provided that its care conditions don’t change). But if you want to have bigger and healthier orchids, then repotting them when they become root-bound is a good way to do it.

Slugs, Snails & Other Pests

Orchids can be attacked by slugs and snails, just like any other plant. The slugs and snails will eat leaves, flowers and roots. They can live inside orchid pots inside the potting mix, or somewhere nearby where they can easily access the orchid. If you notice bite marks in your orchid’s leaves and flowers, then, you have to try to find them and get rid of them.

To successfully get rid of pests, you have to change your orchid’s potting mix. Even if you can’t see any in your orchid’s pot, it’s possible that they’re there. They’re very good at hiding on the undersides of coco chips or bark. To kill them, you have to get rid of every last bit of potting mix, immerse the orchid’s roots in hydrogen peroxide, spray the pot with hydrogen peroxide, and replace the potting mix with fresh. You should then do follow-up checks just to make sure you got rid of the infestation.

What Do I Need to Repot an Orchid?

Repotting an orchid is easy enough, so long as you have the right tools and the right know-how.

What Tools Do I Need to Repot an Orchid?

You stand a much better chance of repotting your orchid successfully if you have a small number of tools to hand.

First, you should consider wearing gloves. These will keep any bacteria in the orchid’s potting mix off your hands; if you have any recent cuts or scratches, the bacteria could enter the wound and infect it. And in some scenarios, you may need to trim away some of your orchid’s roots, and you don’t want to transfer bacteria from your hands to the open ‘wound’.

Second, as you might have guessed, you should also have a tool you can trim your orchid’s roots with. The best is a single-use razorblade, as these are sterile and can make quick, accurate cuts. Failing that you can use a pair of scissors or shears, so long as they’re sharp, and that you sterilize them beforehand (both with soap and by holding the blade over an open flame).

Do I Need Special Soil for Orchids?

You can’t pot an orchid in regular houseplant soil. It’s far from suitable.

The core problem with regular soil is that it’s too claggy and dense. This affects the orchid in two ways:

  • It stops the orchid’s roots from breathing. Orchid roots need access to air so that they can respire. If they don’t have access to air, the plant won’t get as much carbon dioxide, which it needs to photosynthesize.
  • It causes the orchid’s roots to rot. Thick potting mix holds onto water, and since the mix is claggy and soft, this will coat the roots and cause them to rot.

As such, no, you can’t use the same soil you use for other houseplants. Instead, you should use a common orchid repotting mix like coconut chips, pine bark or sphagnum moss to pot your orchid. These three mixes do much the same thing: they allow air to circulate around the orchid’s roots, they hold onto some water but not too much, and they won’t stick to and coat the roots in a layer of dirt that will eventually rot them.

While these media aren’t like your everyday houseplant soil, they’re also not that ‘special’ either. They can be found in any garden center, or online, and they don’t cost much more than normal soil.

Do Orchids Need Soil At All?

Most orchid species don’t grow in soil in their natural habitats. That means any kind of mix: they don’t grow in sandy soil, claggy soils, bark, leaf litter, anything. Instead, they grow on the sides of trees. There are some that live in the ground like other plants (terrestrial orchids) but most don’t.

Despite that, though, it’s still best to repot your orchid into something rather than nothing. That’s because the potting mix holds onto water that the orchid can drink. Organic mixes also contain minerals that the orchid can take in, which help it thrive. If you didn’t pot it in mix, you would have to spray your orchid once an hour (or something crazy like that). It would be an awful lot of effort for no discernible benefit.

So, yes: when you repot your orchid, pot it in mix.

Should You Switch Your Orchid to a New Pot When Repotting It?

It’s up to you whether you switch your orchid to a new pot or not. Most people repot their orchids in the same pot they were in before. Orchids are happy being root-bound, which is where the roots wrap around the inside of the pot. It looks like they have no room and that they’d want the extra space of a bigger pot, but your orchid is perfectly happy this way.

You can either use the same pot as before or a new pot of the same size. You should assess the health of your orchid to decide whether it’s a good idea or not to use the same pot. So, for example: does the pot drain well? May it have been home to a slug or snail infestation? Is it opaque, meaning you can’t see the roots inside? Or would you just like one that looks better?

If you do repot your orchid into a bigger pot, there’s nothing wrong with that. It will want to expand to fill that space, which will take time. When it’s bigger, it will stand a better chance of surviving, as it will have more and longer roots, and more and bigger leaves. One drawback of repotting your orchid into a bigger pot is that it will sit loosely inside it. That’s because its roots haven’t yet made their way into the rest of the medium. It may therefore need the extra support of a stake or two to keep it nice and upright. This isn’t too much of an inconvenience—just something to be aware of.

How to Repot an Orchid

This topic has been covered elsewhere in our site in more depth, so this short guide will only be an overview of how to properly repot an orchid.

Start by taking the orchid’s inner pot from its outer pot. It’s going to be easier and less messy if you do this when the orchid has dried out, so wait until you would normally water the orchid, and then repot it instead. Support the orchid’s main body as you tilt its pot to a 90 degree angle. Do this all over a large bowl so that you can catch any chunks of potting mix as they fall free.

Check the underside of the pot, because if it has holes in it, there may be some roots poking through. It’s sometimes possible to save these roots by threading them back through the holes they came from as you gently pull the orchid from its pot. But if not, they’ll have to be trimmed off.

Massage the outside of the orchid’s pot to loosen the potting mix, all while holding the orchid at a 90 degree angle. It should start to slowly come out. Hold the orchid’s stem, i.e. its main body, with your thumb and forefinger and gently pull at it. Don’t yank at it; apply a consistent pressure. If there are roots poking through the holes in the bottom of the pot, try to straighten them so they can be fed through. Continue until you’ve entirely taken the orchid from its old pot. Trim away any rotten or dried roots, and untangle any pieces of mix still in the root system. Some won’t come away easily, as individual roots can cling to them; if so, leave them be.

If you’re using the same pot, clean it. Line the bottom of the pot with some new potting mix. Take some mix and put it into the root ball of the orchid, then place the orchid into the pot. Pour in extra mix around the sides of the pot; it should hopefully fall down the cracks between the roots. If it doesn’t, gently push it, but not if you meet any strong resistance. I like to water my orchid after I repot it, as this can help the mix move in between the roots. Use regular water with some orchid food added (orchids prefer liquid fertilizer to any kind of solid ‘orchid compost’).