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Aerial roots are something I get asked about a LOT, so I’ve come up with a quick article so you can quickly learn what you can (and can’t) do with aerial roots.
I have a more in-depth post here, specifically about Monstera, but this will help those of you that are trying to get a bit of growth from plants that tend to drop their aerial roots asap, such as Philodendron.
So here we go:
(TL;DR:
- Chop them off
- Use them to anchor your plants
- Increase humidity so they start to climb by themselves
- Stick them to a plank of wood
- Use them to propagate)
1 – Chop them off
If you don’t like the way aerial roots look, you can chop them off. It won’t bother the plant in the least.
I don’t think. Maybe they’re screaming on the inside.
Make sure you use clean scissors (just run them under boiling water) because using non-sterilised scissors is a swell way to introduce diseases to your plants.
If the aerial roots are doing anything, they’re using up your plant’s resources unnecessarily.
If they don’t find something to do, they’ll dry up and stop growing anyway, especially in small specimens that don’t have the energy to spare.
Large specimens send aerial roots along the wall and floor joins where you can’t see them until it’s too late and they’ve removed your paintwork. Do not get a big-ass Monstera deliciosa unless you’re willing to deal with sneaky (and surprisingly fast growing!) aerial roots.
2 – Use them to anchor your plants
This is my Monstera deliciosa, and I pushed the aerial roots back into the soil. After a while, they’ll change into terrestrial roots (no idea how) and serve as a pretty good anchor to keep your plant upright.
Mine have been in there so long I can’t get them out.
Interestingly, they look a bit, er, dead, but they have a whole root system going under the soil.
One caveat here: you need to make sure that your soil is well aerated. You can do this yourself by adding orchid bark or perlite. You can’t really have soil that’s too aerated, just beat in mind that the more aerated it is the more often you’ll have to water it.
If you over water your soil, or it doesn’t have enough oxygen in it the aerial root will rot before it has a chance to take hold.
Also interestingly (at least, it’s interesting to me), plants do do this naturally. It’s obvs just hard for them to do it in a pot because aerial roots aren’t exactly prehensile. But here’s a picture of my Rhapidophora tetrasperma’s aerial root anchoring itself into the ‘ground’ of my terrarium:
And if you’re going ‘eeeew gross it’s all white and furry,’ YOU AIN’T SEEN NOTHING YET.
But it does lead me onto my thrid thing you can do with house plant aerial roots.
3 – Give them more humidity
Unless the picture above really creeps you out. In which case, maybe move onto the next point
Plants do want to climb, and if you give them enough humidity, they will find something. I kinda knew this was true, but didn’t really know how true until I put my heartleaf Philodendron in the terrarium.
Heartleaf philodendrons don’t really grow ‘proper’ aerial roots – in fact, it’s one of the jkey ways you can tell them apart from Pothos.
And for that you should be thankful. Because they. Are. TERRIFYING.
LOOK:
Here it’s trying its best to anchor itself to the glass.
It’s already attached itself to the plastic at the back:
The rhapidophora tetrasperma aerial roots are equally grim:
Considering normal ones look like this:
Why am I showing you these creepy roots?
To prove that giving them high humidity is a GREAT way to get them all excited about attaching to something.
The terrarium is usually at a balmy 90%+ humidity, but before you crank up that humidifier, you can do a quick and dirty hack that involves wrapping a node in damp moss and wrapping it in plastic wrap it works a treat, so if you also wrapped a moss pole round that (i.e wrap the node in moss, then wrap the moss AND the pole in plastic wrap), it’d really help your plant to attach.
OR
You could put your whole plant in a clear plastic bag (or some form of cloche)
Small enclosed spaces with damp soil are naturally humid. The terrarium stays at 90% humidity with no system fancier than my boyfriend spraying it down twice a day with dechlorinated water. Apart from that, we literally never water it*.
*I don’t know why I think this is surprising. It essentially rains in their twice a day. Of course, it stays damp.
4 – Stick them to a plank of wood
Moss poles are all well and good but you have to keep them damp and it’s a PAIN.
Also, a lot of people don’t like the look of them from an aesthetic point of view. Enter the humble plank of wood.
Put the wood behind your plant (make sure you treat it with some kind of varnish if you’re putting it in the soil, otherwise it’ll just rot. Then stick the plant to the plank.
In my experience, plants attach to wood a LOT easier than they do to moss poles, with the benefit that they don’t fall off once they’re attached, which aerial roots tend to if moss poles dry out.
The only example I have at the moment is my Monstera dubia, which is kind of cheating because they grow in a shingly pattern and always grow up planks, but you can grow other plants like that too!
Also, I need to stick down my Dubia because she has a TERRIBLE sense of direction and keeps trying to grow up the back of the plank.
You can’t usually see dubia aerial roots due to the growth pattern but they are CUTE, like little staples.
So, how do you stick your plant to the plank to encourage it to stick by itself?
Er, sellotape
I like to avoid sticking the actual node, because I worry about damaging the growing root, so I stick it either just above or just below the node (or bother, it’s it being a pita).
Then…leave it. They usually stick themselves in a couple of months, but it doesn’t depend on the humidity. If you have dry air, try sticking some damp moss over the node to encourage it.
5 – Use them to propagate
Now, you can’t chop off an aerial root and grow a new plant from that. It doesn’t work. But you can use the aerial root as a started root to give a cutting a bit of an edge. You also don’t strictly NEED an aerial root to prop, but it’s a head start.
There used to be a bit of to-ing and fro-ing about whether an aerial root could ‘change’ into a regular root but they definitely can. I don’t know if they can perform the same functions as an underground root, but I don’t see why not.
Otherwise, why bother growing? Aerial roots can absorb some nutrients from the air, so why not the soil?
I used to think that perhaps the aerial roots that I pushed back into the soil just anchored themselves and that was that, BUT an aerial root from my Thai Constellation has grown into the aquarium, and it doesn’t seem to have any interest in anchoring the plant.
Look at it:
If you want to photos of your aquarium, avoid angelfish. They will photobomb EVERYTHING.
Anyway, look at it go!
Here it is at the top:
Final thoughts
I can only apologise if images of the creepy white furry roots infiltrate your dreams. Imagine having to live with them.
Jokes, jokes, they are EXTREMELY cool and it’s fun to see them doing stuff they don’t normally do. The Rhapidophora is really too big for the terrarium (which is the problem with providing perfect conditions – they grow like freaking WEEDS). I want to take her out but, then she’ll go back to being, er, normal. Perhaps my boyfriend’s right; we do need a bigger terrarium.
Oh, and by the way, it’s totally fine to just leave aerial roots to do their own thing. A lot of plants (like Philodendrons, as I mentioned) don’t really ‘activate’ their aerial roots unless:
- It’s super humid
- They have something to climb up
- Both
If you can’t be bothered to do anything other than attach your plant to a dry moss pole with plant ties, it’s fine. That’s what I’ve done with 99% of mine.