If you have climbing, trailing or vining houseplants, chances are you’ve noticed that as they get bigger, little roots shoot from leaf nodes along their stems. I recently took my Philodendron hederaceum micans off the bookcase to water it and I noticed two things; the all too familiar beginnings of a mealy bug outbreak and the not so familiar fact that it appeared to have become literally quite attached to some of the items on the shelf below it. A few aerial roots had wormed their way in between some plant labels that were sitting on the shelf and had obviously and erroneously decided this was a good place to take root.
The beautiful marriage of roots and plant labels
So what are aerial roots and why had these philodendron roots made the foolish choice to make a bed for themselves in between some plastic labels? Broadly speaking, aerial roots allow a plant to travel. As the plant grows, the stems travel up, down or sideways, depending on the plant’s growth habit. These stems are seeking locations away from the parent plant in which to root, meaning the network of roots and stems gets larger and as the overall volume of the plant increases. The extra ‘footholds’ provided by additional rooting points can provide support and stability as the weight of the plant increases. Once a stem roots via aerial roots, in most cases, these roots are capable of taking up moisture and nutrients. This means the plant increases its chance of survival if the mother plant is damaged or killed because it has many stand-alone offspring capable of being self-sufficient.
My Philodendron is desperate to spread itself about
In the case of this Philodendron, it is able to make a stand-alone plant once it gets its aerial roots down into a suitable place (not the tags from some dahlias). This is why it’s possible to propagate these plants from a piece of stem that has roots on it. You will no doubt have seen people propagating plants such as monstera, epipremnums, Ficus pumila and cissus by placing cut stems in water. The aerial roots start to grow in the water and the cutting can be removed from the water and transplanted into soil once sufficient roots have formed. This is a little risky and some cuttings won’t survive the process of moving from a liquid to a soil-based environment.
There are other ways of propagating these sorts of plants, but I figured the easiest and most fool-proof way to do it with my philodendron was to slot a small tray of soil onto the shelf below the plant. Seeing as it’s making a bid for freedom in all directions at the moment, I’m going to let it creep its way across the soil tray, rooting down as it goes. After about 6-8 weeks, I’ll test to see how attached the stems are to the soil in the tray – if I tug at them and they seem to be pretty well-rooted, I’ll snip those rooted stems away from the parent plant. I’ll turn out the soil and cut every piece of stem that has a root system and a leaf or two away from its neighbours. This will give me a whole bundle of new philodendron plants.
The soil tray in situ
If you have the space around your plants to do this, it’s a really easy way of propagating those that have the capability to produce new offsets via their aerial roots. And hopefully it will save neighbouring objects from molestation.
Have your houseplants ever invaded inappropriate nooks and crannies? Comment below and let me know the strangest place your plants have tried to take root!