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Air-layering is one of those propation methods that seemed a bit complicated, so I didn’t really bother learning much about it.
That was until I discovered that it’s probably the easiest method of propagation out there (especially if you’re propagating vining plants) with the added benefit that if you forget about it, you won’t lose any part of your plant.
You know me, ever looking for the lazy way to produce more plants.
The 5 types of layering
It was only when I was doing research for this article that I discovered that air-layering is part of a whole family of layering methods. There are five different ways of layering, which is simply a way of rooting a plant cutting whilst keeping it attached to the mother plant.
- Compound (serpentine)
- Air (stool)
Tip, simple, compound and mound layering are all various ways of burying a node in soil so that it roots, and then you can detach the mother plant. I go into detail about how to do that in my soil propagation article.
There are slight differences between them:
Tip layering is when you stick the new growth point in the soil.
Simple is burying a node but leaving the growing tip out.
Compound is burying multiple nodes, with the stem between them uncovered.
Mound is a whole big thing I can’t really get my head around but I don’t think it’s something you can do with house plant so we’ll leave it be.
What is air layering?
Air layering is the process of growing roots on the plant’s stem so you can then chop the cutting and pot it up as a separate plant.
What are the benefits of air-layering?
You don’t cut the cutting until it has roots
By rooting the cutting before cutting it, the plant can use energy from its existing root system and leaves to grow roots.
Typically when we propagate plants in water, the plant has to draw energy out of its leaves to grow roots, so we often lose the leaves. Or, we have to provide a very specific environment to grow our propagations from wet sticks.
With air-layering, you don’t need to worry about added humidity or light or anything like that. Keep your plant exactly where it is and propagate it then and there.
You don’t need a propagation jar or extra space to propagate
This is especially useful for people that want to give propagations as gifts (or sell them) but don’t have the space (or inclination to find space) for jars and propagations stations etc etc.
Air-layering doesn’t require much maintenance
You don’t need to change the water, chop off rot, add aeration or anything like that. The only thing you need to do is make sure that the moss stays damp, and it typically takes over a week to dry out, so just make sure to dampen it down weekly.
What equipment is needed for air-layering?
- Sphagnum moss
- Plastic wrap
- Possibly a knife depending on the plant
- Something to secure it with – I use gardener’s twist ties, which I think are just green pipe cleaners with ideas above their station
How to air-layer a plant step by step
Step one: remove leaves
Whether we’re taking a cutting in the more traditional way or air layering, we need to free up space for the roots to emerge from by removing leaves. A lot of people recommend removing multiple leaves, but I usually only remove as many as are emerging from the node we’re propagating.
I’ve circled the node I’m going to air layer. It doesn’t have any leaves, but you can see a dried-up old aerial root, which (fingers crossed) I’m hoping I can reactivate.
if the plant’s petioles are long enough that you can wrap the node without the leaf getting in the way, feel free to leave the leaf where it is (though once the plant is cut, it’ll probably need to be removed so you can plant it up).
Step 1.5: make a notch in the trunk
There’s an extra step for plants with thick, barky stems like rubber plants, and that’s to remove a piece of bark. There are various *technical* ways to do this, but I just take a notch out of the bark using a (clean) knife. If I see no growth in a couple of weeks I make it bigger, but my rubber tree stem is quite thin compared to others, and I’m terrified of decapitating her.
I’m not willing to do this, because my rubber plant has been through enough, but the last time I did this my rubber plant refused to do ANYTHING at the notch site and when I went to make it bigger I noticed it had branched at the top and now had two growth points so I felt like it was the wrong time to be gouging holes in her.
Yes, this is also how to get rubber trees to branch. I’m not quite sure how to govern whether you get roots or new growth, but I’m guessing that the moss promotes root growth.
Step 2: dampen your moss
Moss can be quite hydrophobic, so you need to make sure it’s properly saturated before using it for air layering. Submerge the moss under water for a good fifteen minutes and then squeeze out as much moisture as you can.
I use tap water for this, and have never had an issue, but there are various reports on filtered water producing roots more quickly. It’s entirely up to you, but bear in mind that I have great tap water (brag), and not everyone is as lucky.
Step 3: wrap your node with moss and plastic wrap
Technically this is two steps but I find it easier to do both together.
This is the trickiest part of the whole thing and will make you wish for extra hands.
Theoretically, we’re meant to be wrapping the node in moss, and then covering the moss in plastic wrap so the node is encased in moss and the moss is kept in place by the plastic wrap.
However, I’ve found it easiest to add a bit of moss, then wrap in plastic, and then kind of stuff the plastic. Once you have the plastic and moss in place, secure it with something – I like using gardener’s twist ties.
As you can see, she is not elegant.
In an ideal world, I’d have spread the node evenly around the stem and tied it up neatly like a little parcel (and trimmed off any excess cling film).
However, only putting the node around the aerial root and very little around the back makes it easier for me to keep damp. I can just undo the top twist tie and spray the moss from the top.
Step 4: wait for roots
Check the moss weekly and dampen it down with a spray bottle. It’s waaay easier than taking it all apart, soaking the moss, and putting it back together, and reduces the chance of you throwing caution to the wind and watering with a watering can directly onto the plant.
Water WILL go everywhere, and yet we’ve all done it.
(Just me? Oh.)
Step 5: chop her off
Once you have a decent root system, take you cutting (it really doesn’t matter where you cut as long as the roots are attached to the bit you chop off.
I’ll mark on here where I would chop:
And then it’s just a case of potting her up.
When it comes to pot size, pick a pot that suits the size of the roots NOT the cutting. If you pick a pot that’s too big then you risk the roots rotting. If the roots are small compared to the plant and it can’t stay upright, put the small pot in a larger ceramic one to stop it from falling over. Or pick a slightly bigger pot and fill the bottom with rocks to weigh it down.
How long does it take air-layered plants to root?
It massively varies. I set this up in early March and I’d expect to see roots by April. In warmer weather, you can definitely get root growth in a couple of weeks.
The presence of an aerial root can make this process quicker because the root structure is there, it just needs to be reactivated and turn into a subterranean root.
We’re still not 100% sure why aerial roots have the potential to be dual-purpose aerial/underground roots, but if it makes propagation easier, who cares?
What plants are good for air-layering?
I’m pretty sure that any plant that can be propagated by stem cuttings would be a good candidate for air layering.
I usually use moss or water propagation, however, there are certain circumstances when air layering is best, usually when an established plant is getting older and is looking a bit top-heavy – think plants like Pilea peperomioides or Schefflera that start to lose their bottom leaves as they get older and look a little, er, bottom bald.
Anyway, it can be an absolute nightmare to propagate large segments of plants from cuttings, because they can end up losing a lot of leaves. Air layering allows us to get a decent root system growing without having to sacrifice the plant.
It’s also extremely useful that plants air-layered with moss produce soil roots, so you can plant it straight up
How to water air-layered propagations
Too-wet moss can cause rot and mold, so I just spray mine with water every week.
I’m in the middle of a propagation experiment that found that propagating plants in fertiliser water can speed up the rooting process, so I’m definitely going to try that with air-layering. Just add nutrients to the spray bottle and see if that speeds it up.
I have a whole video on propagating Monstera here, and to be honest, they’re one of those plants that are pretty happy to root whatever method you choose (if you’re having issues with getting your Monstera to root, I have a troubleshooting guide here).
I don’t think air-layering Monstera is necessary, however, if you’re new to air layering they’re a great plant to practice on.
You can also just wrap the ends of the aerial roots, rather than the stem, if you’d rather, and root it that way.
How to make plants air layer faster
There isn’t much you can do to increase the speed at which plants root through air layering, because the main thing you would usually do to speed up the rooting process (increase humidity and aeration) are already taken care of (moss is quite airy plus the plastic keeps humidity in).
The only two things you can do are improve the care and conditions for the mother plant (better light, higher humidity, feeding, watering etc – just be a great plant parent in general) and add a bit of extra warmth.
Now obvs it might be plenty warm, depending on where you live, but if you live somewhere where it’s a bit chilly, a heat mat might help.
My general rule *and bear in mind I made this up from observation* is that if when you’re propagating you require a sweater, a heat mat will help.
Now, I’m currently sat here wrapped in a blanket and my air layering plant isn’t getting a heat mat (because energy bills) BUT if i were in a hurry for her to root, it would definitely help speed things along.
However, if I were sat in a t-shirt perfectly comfortably, any extra heat would probs be a bit much.
Air layering can seem complicated at first (I think it’s the name – it sounds a bit technical because it’s not very representative of what’s going to happen) but it’s one of the easiest and most risk-free ways of propagating.
The extra steps of getting some moss, plastic wrap, and garden ties might seem like a lot more effort than simply sticking a cutting in water, but it’s actually easier – there’s just a little more work upfront.
I think that the minimal maintenance and reduced chance of propagation failing definitely make it worth the initial work. Not to mention that if it does fail to root after a few weeks, you haven’t lost the cutting.