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There are four key aspects to improve if you want to seriously speed up the time it takes for your house plant propagations to root.
Different plants root at different speeds. Snake plants can take months; syngoniums may only take a few weeks.
For those of us that live in cold, dark places, it can seem like it takes FOREVER to root cuttings, but I have some tricks that can help.
Many people swear by rooting hormone, but I like to propagate plants using water (because you can easily check the roots and cut off any root without disturbing the cutting too much), and rooting hormone needs to be dry to adhere to the cutting.
I recently repotted a lot of my plants, and FINALLY got round to chopping and propping some of the leggier plants.
The Syngonium ice frost that had gotten steadily got leggier and leggier until it looked like a kid’s drawing of a tree (i.e. a long trunk and a cloud of leaves at the top) was desperately in need.
The sudden reinterest in the plants I had been accidentally neglecting was due to being sent a Mars Hydro grow light (thanks guys!).
My plants were THRIVING under it, but also they were drying out much quicker and needed more attention.
The fact they were growing like weeds really helped rekindle my love for plants, and I decided that now was the time to make some of my plants look more…like they hadn’t been neglected severely.
I’ve never been very good at propagating because I’m too lazy to remember to switch out the water (keeping the props somewhere where you can’t forget about them is key, it would seem).
Long story short, the syngonium is doing super well.
I chopped of the top and put the new cutting in leca. I also washed the roots of the now-leaf-less roots, and put them in leca too (propping in leca basically takes the pressure of switching out the water, because the gaps between the balls (lol) allows oxygen in).
That was, like, a couple of weeks ago and I HAVE GROWTH ON BOTH SIDES!
Here’s the stump:
Aaaand the actual cutting I took:
Look at all that new growth!
It’s totally possible to propagate plants by shoving them in a glass of water and hoping. But with this article, I hope to give you a few tips that will help you speed up the process and help you understand what helps plants to root.
By the way, all these tips will also help your regular, non-cuttings plants to thrive.
You can use none, one, or all of these tips.
If you have issues with your cuttings rotting, these tips will help but I have a dedicated article on how to stop cuttings from rotting here.
Ever wondered why plants will die from being overwatered but can live quite happily in pure water, er, forever?
It’s all about oxygen.
I have a full article on this topic here, but the td;dr is that plants don’t die from being overwatered, they die from the consequences of being overwatered, which is lack of oxygen.
That’s the reason we recommend using an airy soil mix: to literally get air to the roots.
There is a balance to be struck here – if you’re an overwaterer by nature, you can go super airy – as long as the roots have some contact with the substrate (so they can extract water from it) it’s all gravy.
If you’re an underwaterer, don’t go so airy that you end up letting your plants dry out – airy mixtures can’t hold as much water as denser ones.
Or you could cut out the middle man entirely and keep your plants either in leca (full guide on how to do that here) or submerge the roots in water (your article is here – it’s specifically about Monstera, but the same rules apply to other plants).
Increasing the amount of oxygen in your propagation vessel will massively speed up the rate at which your cutting roots.
So how do you increase the amount of oxygen in the water?
Change the water frequently
This is low tech but high energy. As someone with suspected ADHD, this isn’t something I can manage easily. I just forget until the cutting starts dying, by which time it’s usually too late.
I use tap water for propagating my cuttings, and my general root for answering the ‘can I use tap water to propagate cuttings?’ question is to just ask if you can drink it. If you can, then your plants will probs be fine.
By the way, I’ve recently run an experiment where I changed the frequency of changing the water. Changing the water of your props every day makes them root MUCH faster. Like, in a week. it’s now been three weeks and the others have barely grown at all. bad news for lazy propagators!
Add an air stone
Air stones and pumps are pretty low cost to both purchase and run.
The downside to them is that they’re noisy. Even the ones that claim to be quiet.
Please take my word on this, because it’s one of those things that I have a weird amount of expertise in. My boyfriend has aquariums (multiple) and we’ve tried a LOT of air pumps. Even those branded as silent will start buzzing after a few weeks.
My tips are:
- Keep it out of a room you spend a lot of time in and/or
- Put it on top of something that will absorb the vibration, like a dishcloth.
Add oxygenating plants
Again, this is a result of years worth of experience in aquariums.
If you follow my Instagram, you’ll already be familiar with my ‘kitchen sludge’ propagation box. It’s basically a small aquarium (obvs no fish or anything, bar the odd trespassing snail) with an inch or so of water in the bottom and a load of java moss.
Java moss produces oxygen all by itself. It is EXTREMELY undemanding. It doesn’t produce as much oxygen as an air stone, but it’s much more low maintenance, and crucially, QUIET.
Marimo moss balls are another option, but I’ve never personally used them. I know some countries are having issues with them as they can harbour fugitives in the form of zebra mussels.
Not technically water propagation, but close enough.
Leca does have an initial outlay (but you can get it pretty cheap on Amazon) but it’s reusable, so that’s good.
Here’s my syngonium cutting set up:
I got a 50 pack (which, in hindsight, was waaaay too many) of the little net pots from AliExpress but a nursery pot (cut some slits in the side if you’re feeling fancy) will do the same job. And that’s a peanut butter jar it’s sat in.
All the leaves died. It’s the price one pays for propagating under grow lights BUT you’ll notive that I have a new leaf growing. It’s been two weeks. And if you look closely you’ll see another growth point on the stem.
Leca absorbs water from the vessel below and provides oxygen (because there’s gaps bettwen the stones) – it basically eliminates the need for you to change the water*.
*For the purposes of increasing the oxygen. It does not, alas, stop the water from getting all grim and algae-fied.
Humidity is definitely very important when it comes to growing roots BUT it’s not as crucial as increasing the oxygen and light.
Where humidity does help is in keeping the old leaves. This very much depends on the plant though, and the number of leaves. It’s helpful, but not a guarantee you won’t drop leaves.
Humidity dramatically increases the health of the plant (again, depending on the plant – a cactus wgaf) and you can give your cutting a great start by giving it seriously high humidity. Your cutting may decide it has the resources to produce multiple growth points rather than just one.
In short, increasing the humidity may help your plant become more aesthetically pleasing.
But since many of us keep plants because they’re aesthetically pleasing, it’s worth mentioning.
Add a humidifier
This is the easiest option but isn’t without its downsides. There’s the cost of the humidifier itself (I recommend this Levoit one), plus the cost of running it (though they’re not particularly greedy).
Propagate your plants in a terrarium
I personally think this is the best way to create humidity because you can use anything that’s clear (like a big plastic box or something) add some moist moss or coir as substrate and add your plant, pot and all.
Or you can go all out, buy a big fancy terrarium (or an aquarium) and make it look as aesthetically pleasing as you like.
The moisture in the substrate will evaporate and keep the terrarium humid. Add a heat mat and a grow light and you’ve got a perfect propagation box.
The only issue I’ve had with using my terrarium as a grow box is that it isn’t big enough. The plants go WILD in there and quickly outgrow it.
Get a small indoor greenhouse
I’m currently using mine as a grow light stand because my plant room is pretty humid.
As you can see, it’s not a very efficient use of the space BUT it’s a pain finding ways to suspend professional grow lights without drilling holes in the ceiling. If anyone has ideas, please let me know.
I’m thinking of perhaps a really nice wooden clothes rail.
These greenhouses are pretty cheap from Amazon. They’re NOT very sturdy, but they serve my purposes fine. It comes with a plastic cover that will create a perfect humid ecosystem for your cuttings.
Light is one of those things that divides the house plant community when it comes to cuttings.
In general, more light is always best BUT bright sunlight can be too strong for delicate cuttings. It’s too hot, too direct, and just too damn strong. I can definitely see why so many house plant experts recommend keeping your cuttings out of the sun.
Use a grow light
I know, I know, I said that bright light isn’t good for house plant cuttings, but grow lights and sunlight isn’t the same.
Grow lights are bright, but they’re not as hot, and the light is diffused in a controlled way.
I totally attribute the speed at which my cuttings root to my MarsHydro grow light. I literally noticed a difference in my plant’s growth in a couple of days.
Put your cuttings by the window
Ideally, we’re looking at bright, diffused light – a west or south-facing window with a sheer curtain over it to protect the cuttings from the heat and harsh light.
Btw, frosted glass windows – like the kind you get in a bathroom – work really well for cuttings.
But I get that that’s kind of a big ask.
Especially when an east-facing window does nicely. Here’s a picture of my Ctenanthe lubbersiana cuttings after only a couple of weeks:
Is anyone else SHOCKED that Ctenanthe propagates through cuttings? I thought it was division only, but no!
I almost gave up on them (despite only taking a couple of weeks to root), because was sure Summer Rayne Oakes had lied to me but NO, there they are!
I changed out the water a couple of times (for that sweet, sweet oxygen) but she mostly did it on her own!
Warmth is one of those things that isn’t really talked about in the house plant community, even though it’s pretty commonplace for gardeners to grow seedlings on heat mats.
It’s something that really help your plants grow faster and root quicker, and it can also help increase humidity.
Put your propagations on a heat mat
BUT putting cuttings on a heat mat really can help speed up rooting. I always used to think it because the cutting would think it was really warm above ground, so the roots had better grow so then leaves can grow and take advantage of the nice weather.
As it turns out…no.
The warmth just speeds up cell division at the cut site.
Heat mats are a fairly inexpensive way to warm up your plants.
Use a grow light
If you have a big-ass grow light like I do, you’ll know that it’s pretty toasty under there. A heat mat would DEFINITELY be overkill. I’d end up toasting the guys.
Smaller grow lights are less likely to emit heat, but if you have any kind of light bulb that emits heat, try putting a cutting near it (though make sure it has enough light – some LED lights are fine, but it depends)
Put propagations in a warm place
It can be difficult finding a warm spot in the wilds of our homes that’s the right kind of warm.
I mean, sure, there’s a lovely warm spot next to the radiator, but that’s too warm – it’s like the light from the sun…just a bit, you know, much.
The airing cupboard is too dark, the oven is too hot and dry…See? It’s hard.
Maybe if you could convince your cat to cuddle your props?
What about fertiliser?
Elsewhere on this site there will be articles I haven’t updated, so apologies for that.
Common consensus is that adding fertiliser to cuttings is at best useless and at worse, harmful.
No no no no no.
I’ve recently propped my Philodendron brasil in 10 different ways and the one in fertiliser (GH Flora series – I eyeballed the amount, but the smallest amount I could tip in, in a 250ml glass) water propped so much quicker than ALL the others.
Interestingly, all the root growth came out of the aerial roots. The next quickest was the water with Superthrive added, but the new roots came directly from the node. Hmm.
In my experience, increasing the oxygen to propagations has the most noticeable impact on how quickly they root, followed closely by light. Warmth and humidity also have a significant impact, but definitely a smaller one than the other two factors.
I don’t recommend fertilising cuttings. Giving a plant fertiliser before it has roots is like offering someone that’s been seriously hurt a sandwich. Like, it’s a nice thought but also 100% not what they’re after right now.
Ok, I’ve been experimenting with propagating in nutrient water and it REALLY speeds things up. See, sometimes you have to try things out for yourself!
Always sort out oxygen supply before food is probably a decent rule to live by! And on that very profound (well done me) note, I shall leave you.
As always, feel free to leave me any questions and I’ll
google them try to answer if I can!