Glossary of Houseplant Terms

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This is a dull but necessary post. Well, not necessary, but possibly useful. Leave me a comment or email me if you have any words you want me to cover.

Aerial roots

Aerial roots (sometimes called prop roots)are not the same as underground roots and don’t always do the same job. In most cases, their function is to provide support for the plant by clinging to trees.

The aerial roots of some plant species absorb moisture and nutrients from the air, but you usually can’t propagate a plant with just an aerial root.


A fancy word for a cover pot.

Because this world is MENTAL, it’s difficult to come across beautiful ceramic pots that have drainage holes. As we all know, plants NEED a drainage hole in order to survive (read why here) – if you don’t you’ll have to work your arse off to prevent root rot.

So what we have to do it keep our plants in plastic pots (because who needs the environment?) and then put the plant plus the plastic pot in the beautiful pot. MADNESS.

In most cases, you can keep your plant in its nursery pot for a while, rather than buying another plastic pot. If you’re anything like me, you’ll have a shed full of plastic pots of varying sizes.


Cataphylls are like leaves, but, er, not. Proper leaves are called ‘euphylls’, and do all the photosynthesising.

Cataphylls are smaller and perform a couple of different functions, the most common one being thorns and spines. Sadly, they only perform their function after they die.

The cataphylls house plant parents usually see are the ones on philodendron and they act as a little protective layer for the leaf when it’s growing, and then dies.

I leave mine on, but you can remove them if you want.

They’ll drop off on their own eventually.


Also called coco coir. It’s an ingredient in posting mix made from the outer husk of coconuts. You get it in various levels of chunkiness, though the standard stuff is pretty soil-like. It retains a lot of water but doesn’t provide any nutrition (unless you soak it in nutrient water.


Dormant means that something isn’t actively growing.

It’s a myth that all plants go dormant. When they stop growing in winter they’re not dormant, they’re just using their energy to keep their leaves alive, rather than wasting it growing suboptimal winter growth.

Not many house plants go dormant as part of their natural cycle, because they’re tropical, and therefore there’s no real winter season.

However, some plants show all the signs of proper plant dormancy, which looks to all intents and purposes as though the plant has died.

From a quick search, it seems as though Alocasia are the worst culprits for this overdramatic behaviour. If they detect an extended drop in temperature, they drop all of their leaves.

See? Drama.

What the plant is doing is getting rid of any dead weight (who needs leaves when it’s cold and dark?) and concentrating all its energy on its tuberous roots. Chances are, it’ll start putting out new growth in spring and we’re all happy.

TOUCH WOOD none of my three alocasia have gone dormant. my stingray has put out a new (albeit tiny) leaf, and my Amazonica bloomed. My Zebrina got off to a rough start (I think low humidity in the supermarket I bought her from was the issue) and dropped all her leaves but three.

Those three are fine, but there’s no sign of any more.

Don’t blame her tbh.


Plant food. Comprises of the three elements needed for plant growth:

  • Nitrogen – leaf growth
  • Phosphorus – Development of roots, flowers, seeds, and fruit
  • Potassium – regulates Co2 and the movement of water, and triggers enzyme activation.


The bit between the petiole and the top of the leaf – the leaf’s neck!

monstera deliciosa geniculum


Guttation occurs when the plant takes up more water than it can use or expel through transpiration. The pressure of the water builds up in the leaves and forces the water out in the form of droplets on the ends of the leaves.


Growing plants using water as a substrate, not soil.


Measures the ambient humidity of the air.


The complete flowering part of a plant. So it could be the flower spike and flower of an orchid, or the spathe and spadix of a piece lily. It’s the whole flower mechanism, not just the individual flower.

So on a spider plant, the inflorescence is the whole thing – flowers, babies, stem:

spider plant


Lightweight expanded clay aggregate. It’s a substrate used in hydroponics. It’s basically clay with holes in it. I have an introduction to leca here.


When a plant grows sparsely – the leaves are smaller and far apart on a leggy plant. I have a post on leggy growth here.

Neem oil

An oil pressed from the fruits and seeds of the neem tree, as evergreen tree from India.

It’s useful to clean plants and is a great way of getting rid of pests because it stops them from reproducing.

Don’t use it outside because it affects bees.

There are a lot of people out there who claim it’s not potent enough to get rid of severe infestations, but it works for me.


The bit on a stem where the leaves grow from. Normally looks like a little bump. You need a node if you wish to propagate your plant.

Nursery pot

The pot your plant comes from the nursery in. I like to keep my plants in nursery pots, because it makes it easier to tell when they need watering.

Oedema (in plants – am not a doctor)

When the roots take up too much water too quickly. Pressure builds up and the vessels burst. It often looks like little red spots in the leaves, but can also be seen in the form of corky spots, or pimple-like bumps. Ew.

Fiddle leaf figs are notorious for getting it because they’re drama queens.

If you see signs, remove the affected leaves – they won’t recover.

The main cause of oedema is overwatering – learn how to stop overwatering here. It’s sometimes caused by overall bad plant parenting or even as a side effect of some insecticides.


Perlite is a type of volcanic glass that can retain water but helps to stop soil from being compacted, so it adds drainage but prevents soil from drying out too quickly. We love.


The petiole is the skinny bit that attaches the leaf to the stem.

Celery and rhubarb are petioles. The more you know.

Petiolar sheath

The petiolar sheath protects the new leaf as it grows – a bit like a cataphyll, but it’s not a modified leaf, it’s just a bit of the petiole that the new leaf emerges from. The petiolar sheath goes brown like a cataphyll, but doesn’t fall off (because it’s more attached).


To make more plants from a parent plant. There are LOADS of different ways to propagate plants. If you’re new to propagating, start here.


So, you’ve spent £200 on a variegated monstera and you’ve heard that they can revert.

This just means that you’ll have to keep an eye on the new growth, because it can come in completely green, and you may lose the variegation entirely.

So your £200 plant is now worth £20.


You can help to preserve the variegation by cutting off the green leaves.


A plant of a genus that comprises the peat mosses. I took that sentence straight from Wikipedia.


When the zones of the leaf are different colours. This does occur in nature, and I always assumed it was like the plant version of albinism.

Some plants, like spider plants, are naturally variegated. Other plants, like Monstera Albo Borsiagiana, occur naturally in the wild but can be easily propagated in a commercial setting.

And then we get plants like Monstera Thai constellation (I have one! I love it!) that we created by botanists and don’t occur in the wild. The benefit if this is that plants that have variegation built into their DNA don’t revert.

Worm castings

Worm poo. Good for fertilising your plants gently. Should I start a worm farm?? I might start a worm farm.

Caroline Cocker

Caroline is the founder and writer (and plant keeper) of Planet Houseplant

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