Aerial Roots on Orchids: 7 Important Questions

Aerial roots are not common in other household plants. If you have just come across your first orchid, you might wonder what the projections on the outside of the potting medium are. Aerial roots in orchids can bring up a lot of questions and concerns, which I’ve tried to answer below. If there are any questions that haven’t been answered, please leave a comment in the box at the end, and I’ll do my best to get back to you.

Can You Cut Aerial Roots?

Never cut aerial roots since they are responsible for providing proper nutrition and adequate hydration for the orchid. Trimming aerial roots on orchids is not recommended.

Not only do aerial roots absorb humidity of water droplets and nutritious micro-elements traveling on wind currents, aerial roots also increase the amount of energy by photosynthesizing.

Again, never cut the aerial root on orchids since this will hinder the amount of nutrients and water absorption your orchid receives.

Orchids never want their roots to be cut, whether they are roots that sink into the potting medium or aerial roots. Never. Just don’t do it. Roots are one way the orchid has to tell it’s in a safe environment and that it will be secure enough to use that enormous amount of energy stored up to produce a flower spike.You’re in luck!

There’s a video about this exact content so you don’t have to read all 3,000 words below. 🙂 https://www.youtube.com/embed/aIS22UxunT8

Where does the name “aerial roots” come from?

The name aerial comes from the Greek prefix, -aer or -aero which refers to oxygen, gas, or just plain air that we breath. If you like word games, you can easily relate to other words where air is related, like aerate (to expose to air circulation) Aerate cake batter…

Orchids in Bloom

Another example of -aer is aerobic exercise. In this type of cardio, the cells have sufficient time to perform agas exchange without depleting completely. It’s the anaerobic (lack of oxygen) that makes your muscles hurt the next day with lactic acid.

Anyway, back to orchids…

Why does the orchid grow aerial roots?

What makes orchids have roots that pertain to air are that orchids don’t grow in soil—at least the epiphytes don’t. As seeds, these orchids attached themselves to trees when they were floating through the air. They grew roots that gripped firmly onto the tree bark, about ⅓ of the height of the tree.

This height allowed the orchid to get enough indirect sunlight since the dense canopy of leaves above them made it quite dark at the soil level below. They’d never survive with such low light.
The soil (contrary to popular belief) in the rainforest is quite poor in nutrients. The dark black color mainly comes from charcoal and decomposing elements that have fallen from above.

With this new location, the orchid needed to find a way to survive. By developing aerial roots, the orchid could grasp nutrients that we also floating through the air. (Source)

With many flowers nearby, an abundance of nutrients, water, and minerals, the aerial roots had plenty to survive.

Phalaenopsis Orchids

What do Aerial Roots Look Like?

You’ve been cultivating your orchid for quite a while and you see a new projection coming form the stem. How do you know this is another aerial root or a flower spike?

The end of aerial roots will be smooth, and to a certain extent, pointed or slightly rounded-tip at the end. A silvery white color will predominate and when you water, it turns green. Yep—all root.

A flower spike with be bumpy at the end, with sharp ends, and possible three or four funny tiny nodules. When you water it, it doesn’t change color, since it already is a greener shade than the root. As it matures, the green color will become more vibrant and harder.

An orchid with prominent aerial roots is the Vanda. These aerial roots are part of the spectacle itself, and many orchid enthusiasts display their Vandas in hanging baskets. The flower spikes on Vandas never disappoint—never.

Do aerial roots Like Being Root Bound?

Some of the aerial roots clung to the tree to provide a safe place to hang onto during strong winds and rain storms. But to keep them in a home environment, we can’t hang all the orchids up in hanging baskets or place them on wall mounts.

We need to  pot them or mount them.

In the pots, the orchid roots won’t have full access to air. The only thing the pot  provides it is the firm surface area to cling to. Orchid roots will grow to the sides of the pot, never concentrating in the middle of the plant, as other household plants do. They prefer the security of attaching their roots to the rough bark-like surface of the pot.

This is why the roots prefer to be placed tightly in a pot, then to have excess room to grow, in bigger, wider pots. Root-bound is not a problem that makes the orchid unhappy. To the contrary – it looses it’s stability and security if it grows in a pot too big for its roots.

Orchid and Books
Orchids and Books

Why do Orchids Grow Aerial Roots?

In short, stability. Aerial roots make the orchid safe and secure, signaling it’s safe to send out a flower spike. With unstable roots, the orchid will not send out a flower spike. (Source)

As if the orchid followed a pyramid from Maslov’s Hierarchy of Needs, they place safety before propagation of species. Let’s make a crude comparison, so bear with me on this one. Let’s say you just got evicted and have no where to live. With a suitcase in your hand you look for shelter.

Are you really wanting to dress up, kick on some high heels, and go out and dance? I think not. Other things preoccupy your mind. Your own safety is one of them.

Now, let’s say you’ve given up all hope of finding a secure place to stay and now need a new environment to live in. You start looking for other places to live.

Orchids do the same to some extent.If they don’t find the potting medium secure and can’t relate to it well, then it will send out the last “save me” sign as a beautiful flower spike. This is done so hopefully a bee, butterfly, or other flying critter will pollinate it and its species will go on after it dies. You might think that because your orchid has produced a beautiful flower spike, it’s thriving.

Nope. It’s dying.

Take good care of the roots, and you’ll have a healthy orchid for a long, long time. In common household plants, you can tell the health status by looking at the leaves. For an orchid, verify the roots. If there are no aerial roots, that really isn’t a problem, but if there are many, then your orchid is doing quite well. Keep up the good work.

 If you have only aerial roots but he roots inside the potting medium are dying, then you need to change media.

Do Aerial Roots have a Purpose?

Besides providing extra stability, aerial roots aid in photosynthesis. Since the orchid had to give up soil altogether, attaching itself to a tree, and clinging to the bark as tightly as it could, there had to be something that it could do to absorb more energy. The roots adapted to be able to photosynthesize, like the leaves to. (Source)

Multitasking done like a pro.

The velamen not only helped the roots attach to the tree, but they also captured the sunlight and with the chlorophyll present in the cells, it helps transform sunlight into energy.

This is why it is so important to keep the orchid’s aerial roots above ground and use clear, plastic pots at all cost. For more information on this, you can check out this article about choosing the right pot for your orchid.

Terracotta pots for orchids

Do Aerial Roots Dry Out Faster?

Since the roots are above the potting mix, aerial roots tend to dry out faster than the ones buried inside the pot.

To make sure aerial roots don’t dry form low humidity, you can do two things:

(1) spray or mist them every morning, or

(2) cover them with a very, very thin layer of lightly humidified sphagnum moss. This is called the top-layer treatment. The second is a great way for office orchids to survive the air-conditioner and heater, both which suck humidity right out of the air.

How do You Repot Aerial Roots?

Since you have to keep the roots, and make sure they are aerial, what’s the right protocol during repotting time? Do you shove them down in the pot? Or let them be?

If you are just disgusted with the way the roots look, and there are a ton of aerial roots coming out of the top of your pot, then yes you need to repot. One rule though: keep aerial roots in the air and roots that were in the medium, in the medium. Aerial roots on orchids are not as malleable like the humidity-soaked roots, sitting in contact with sphagnum moss.

The brittle roots that have been sitting above the potting medium can become more malleable when soaked in lukewarm to warmer water—never hot.

Let the orchid soak.

The majority of the aerial roots can be repotted to fit down under the potting medium when in their new pot, but be warned, they will die off. They have accustomed to being in the air and will not adapt well to the new medium. The still can absorb, but most will die.

Newer roots are better at adapting than older roots are.  I wrote an entire article about this subject in more detail, which you can read by clicking here.

Don’t Stop Learning!

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Orchid Fertilization

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If you subscribe to my newsletter, I will send you a 14-page guide on the main tips of orchid fertilizer. It is downloadable and you can print it out on your computer. I designed the guide to double up as a coloring book, just to make it fun.

Is there a way to hinder the production of aerial roots on orchids?

If aerial roots are just too unsightly for you, then there is a way to hinder their growth. Make a note though that I am totally against this method of hindering aerial roots on orchids. This method will make your orchid suffer and it most likely will not bloom that year.

Remember that the orchid sends out aerial roots to make itself more stable. If you have a massive phalaenopsis (moth orchid or butterfly orchid), for example, with large leaves, and a tiny little root system, the aerial roots want to stabilize the plant—mainly so it won’t fall over.

When it produces the flower spike, the weight of the flowers can make the entire plant topple over, crashing to the ground. To avoid this, the orchid sends out aerial roots as feelers, looking to latch onto anything around it.

To hinder the production of more aerial roots on your orchid, take away it’s stability. Replant the orchid in a pot that is bigger than recommended.

When you give the orchid a bigger potting medium it will want to explore to reach the sides of the pot. Once at the sides, it will cling to them. This will take months, maybe years.

Once the orchid has reached the sides of the pot, it will start to produce more aerial roots. So you have saved a few months without aerial roots.

Problem solved.

You have eliminated the production of aerial roots until the lower roots reach the sides of the pot – one year? Two maybe?

It’s a temporary solution, but one that works.

For the orchid, it’s not the best solution though. This will stunt growth and the orchid may not bloom that year.  Keep in mind the trade off of having a happy orchid or one that is suffering, looking for stability and security. 
Now that you know all aerial roots, it’s time to get your hands dirty. How about mounting orchid?  You can check out some of our tutorials on how to repot orchids with sphagnum moss or how to provide the right humidity for your orchid until you’re ready to get your start your first terrarium.

If there is any other question about aerial roots that I have not answered in the questions above, please leave me a comment below. I’ll do my best to answer it for you. Comments may take a few days to get approved by my anti-spam, so if you don’t see your comment, don’t worry. It will show up eventually.

If this information was of any help or clarified any doubts you had, please mention so in the comments. I love to interact with other orchid enthusiasts and we can share from our experiences.

Happy cultivating!

Signature Amanda Matthews


Amanda Matthews

Amanda Matthews is a theological professor, author, pastor, and a motivational speaker. She's passionate about spreading hope and teaching. Her hobbies include biking, cultivating orchids, and exploring nature trails. She now lives in Kansas, while raising her two children. To read more, go to https://orchideria.com/about-the-author

23 thoughts on “Aerial Roots on Orchids: 7 Important Questions

  1. I got this web site from my friend who shared with me on the topic of
    this web page and now this time I am visiting this website and
    reading very informative content at this place.

  2. I have a spike that appears to be drying up but at the top of it I have nice dark green leaves (one of the new) and air roots. Do I just leave it alone? I am guessing the growth on the top of this spike won’t survive.

    1. Hi Jeena,
      I think what you are describing is a keiki, a new growth on your orchid spike. I am not sure if the leaves you described were on the spike or on the actual stem of the orchid, where the normally would be. In either case, you can leave it alone. If it is a keiki, the spike will dry up just until above the keiki. You can read more about keikis on this page: https://orchideria.com/orchid-keikis/ If it is just a normal spike drying up, (and the new leaf growth is on the bottom, not on the spike) then there is no need to cut it if you don’t want to. You can read more about that here: https://orchideria.com/how-to-care-for-orchids-after-blooming-complete-guide/
      -Amanda

    1. Hi Natasha,

      The aerial roots are fine just hanging out in the air. As long as there are healthy roots in the pot that are attached to the potting media and don’t wobble around, then the aerial roots are fine just hanging there.

      -Amanda

  3. Hi Amanda – Thank you for the reply. The new leaves are actually on the Stem I guess you would call it. I am seeing diagrams with both spike and stem used. In the past the stems have come from the base of the plant but on this particular plant, there are leaves that have grown after trimming down to a node after blooming and now there are roots growing below the new leaves in the middle of the “stem”. One of those stems is now drying up but the leaves and roots appear to be fine … for now.
    I may be explaining this completely wrong.
    Is there a way for me to sent a photo?

    1. Hi Jeena,

      A picture would be nice, but because of the thousands of spam I get a month, my website automatically sends comments with pics to the trash. So sorry. If the roots are growing perfectly fine, then there shouldn’t be a problem. The orchid could decide it doesn’t want to grow the keiki and it might shrivel up. If it does, you can just leave it there, since the orchid will absorb some of the nutrients back into the stem. Either way, with new roots and new leaves, it seems like your orchid is doing well.

      -Amanda

  4. Hi Amanda, thank you for doing this article and video on aerial roots because I don’t like hearing that people cut off aerial roots just for aesthetic reasons. I’ve learned from all the orchid care videos I’ve watched on YouTube and Pinterest that aerial roots could save the life of one of my orchids if the roots inside the pot die off. I believe people, mainly beginners,just haven’t thought of that. God bless you!😇

  5. I love ariel roots. Maybe they wouldn’t get such a negative reaction if people didn’t call them unsightly….or this article makes them sounds like something atrocious…maybe put them in a better light and people’s attitude towards them will change!

    1. Hi Anthony,
      Thank you for the feedback. Some people love aerial roots, others not so much. I agree my wording choice of unsightly was a bit harsh. On the other hand, I disagree about the overall attitude of the article. I wrote it so people who don’t like them (those who agree with the unsightly) will change their minds and see how important they are.

  6. I would like to repot my phals but there are already many long roots growing through the holes on the sides and bottom of the clear plastic pots that I really don’t want to split open. Is it okay if I cut those roots off before repotting?

    1. Hi No Green Thumb,
      I would highly advise against it. I know sometimes it may seem complicated, but start the task when you have a couple hours of free time. If you soak the orchid with all the roots, they’ll come out easier. I know it’s hard, but if you cut them, you risk losing a portion of how they fed. I wish you the best in getting this done. I know it isn’t easy.

      -Amanda

  7. Some of my orchids aerial roots have found the pots of nearby plants and pushed their way into the soil. So now I have one or his that is “connected” to four other plants. Can they be used to propagate new orchids? What do I do if I need to move the plants? I can’t find any references to this situation.

    1. Hi Stacy,
      Thank you for reading my article and for leaving a comment. The tips of the orchid roots can sense the environment and its strange that they would find their way into another pot. The main reason for this is there is something in their pot that they aren’t so happy with. Unfortunately, you can’t use those to propagate new orchids, since they serve mainly as fixation and absorption of water and minerals. They will do nothing for growing a new plant. I’d repot, carefully “unhinge” them from their neighbors (LOL) and repot them. It’sa good sign that the old potting media might need changed.

  8. Many thanks for the interesting article, which I found when searching for advice on whether or not it was OK to trim aerial roots. Now I know!

    From reading all the way through, I also took on board that the production of a flower spike is some kind of last resort, or swan song, indicating that the plant is dying. Then, reading the answer to a subsequent question I read that hindering the growth of aerial roots will make the plant suffer so it won’t bloom. Sorry, but I found those two ideas to be in conflict with one another, leaving me slightly confused. Could you please clarify?

    1. Hi Brian,
      Thank you for that comment. I need to clarify that better in my article, so I appreciate that you pointed that out. In most all cases, the flower spike is normal and to be expected yearly or biannually. That is how they grow in nature and reproduce. In some cases though, when care is not right and the orchid is suffering, it will give in to producing the very best flower it can, then it will die. This is a bucket wish list, and the orchid id trying to keep it’s species alive by being pollinated, then liberating millions of seeds. So it focuses the maximum that it can on the blooms, then it dies. Some orchids will produce humongous amounts of aerial roots, indicating that the potting media needs changed. None of the roots like what is in the pot, so they grow outside of it. By trimming the aerial roots, the orchid has less chance to capture nutrients and water from the air. If the orchid doesn’t have the nutrients it needs, then it suffers and produces a flower spike. I hope that explained the two paths the orchid can take when it decides to produce a flower spike: either it’s very healthy, or it’s really bad.
      -Amanda

  9. Just learned from this article that mine are likely dying even though the leaves are hard and green and there was new aerial root growth the past couple + months; wow! I had no idea that the keikis and flowers that are growing on one of my orchids and the flowers on the other one were indications that they were trying to save their species. So thank you!!!!

    Here’s what did to verify this: I realized that though they prefer the diffused sunlight (SW) behind a bay-type window, they were soaking in water that was not evaporating like I thought (because truly I rarely water them). I never checked the pots in which their clear plastic pots sit in. Also, after reading the article and the one you linked to on the plastic pots (or someone did), I begin to wonder are the cover pots (glazed clay) that the florists put them in good for them, as it blocks out light?

    So after all of this, here’s what I did ( I hope this will help them): since you mentioned that roots starting to grow out of the pot may indicate need to repot, I took them out of their clay and plastic pots and gave them a mix of their old bark soil with some new dry bark soil. I made sure to keep the mix semi-moist and a tad towards drier, because they were swimming in wet bark. A note that the roots were soaked in the one without the keikis, but not rotted and nearly soaked in the one with the keikis, but still clear (versus yellow to browning in the other one.) So having put them back into their clear plastic pots and lefting them out of the clay pots, I put them back in the same area behind the window where they were and seemed to like the light . Note that they are on the floor (ceramic) over paper towels for now until I can find saucers to put under them. And they have two ficus trees (a smaller one and medium bushy one) to help diffuse the light, plus other items on the balcony that diffuse the light too. I hope I did well by them.

  10. Is it ok to tie the aerial roots together on the rod that came with the orchid? Or must you just let them grow however they’d like?

  11. Hi Amanda,

    Your article is one of the best I’ve found! Thank you.

    I have a question about the loss of the inside roots. I was/am trying to save my orchid but the inside roots need to be removed asap as they are rotting. There are several aerial roots, but no inside roots look good. Is the plant beyond saving?

  12. Hi Amanda,

    Thank you for this informative article!

    I live on Kauai and we have beautiful Phalaenopsis orchids growing in pots attached to our front porch wall that have bloomed multiple times over the past 1 1/2 years. The aerial roots are growing up the house walls and I’m concerned that they could be damaging the wood? Any insight on that? Thank you!

  13. Hi. I have a question about the clear pots: if the roots need light for photosynthesis, is it a good idea to put the clear pot with the orchid inside a decorative pot? All the pictures of orchids I see on the internet, Including in your article, show the orchids in decorative pots. What’s the point of the clear pot then?…
    Thank you for explaining that the orchids need stability and they like to have their roots squeezed inside the pots. I repoted some of my orchids in much larger pots than they needed because I thought that the crowded roots suffer. All the roots inside the pots died (they became brown and squishy) and I have no idea why, but probably the larger pots had something to do with it. I won’t make this mistake again lol. Luckily, they have plenty of aerial roots and I hope the orchids will survive though.

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