Everything You Need to Know About Repotting Houseplants

Roosie
Published on July 25th 2020
26
A man repotting houseplants at a bench
If you're looking for answers about repotting plants, you're in the right place!
In this article, I'm going to try and give you an overview of roots and their importance and explain why we repot plants, how often to repot houseplants and some instruction on how to repot plants successfully.
This article won't detail how best to water your plants. You can find that information here:

How often should you repot your plants?

How often you should repot your plants depends on a range of factors - there's no one-size-fits-all answer.

Learning is key

The more you learn about your plants, the better! If you have some idea of what your plant is, even if that's just a general idea of the genus or type of plant, for example, a Succulent or Orchid, that's a good place to start. You can read more about those here:

What plant have you got?

If you'd like to find out more about your plant, try Plant ID in Candide or ask the wonderful community by posting a photo! #PlantID
It's good to know a bit about your plant as this can influence your repotting decisions! Some plants actually like being a bit rootbound.
For example, all these classic houseplants will happily grow in a smaller pot:

How long's it been?

It's great to know how long your plant has been in its current pot, but we don't always know that!
Don't worry, its simple to work out if your plant needs a repot if you know what to look for. Have a look at your plant at the base of the pot, can you see any roots poking out? Does it look out of balance for the pot size, with the potential of toppling over?
Close up view of young gardener woman holding green plant with root system in soil ground on light background

3 Super simple steps to repotting a plant:

  1. Remove the plant from the old pot
  2. Remove old soil and loosen roots gently
  3. Place plant in a new pot with fresh soil.

Too simple? More details below!

1. Remove the plant from the old pot
This can be harder than it sounds when the plant has been in there a while! Gently squeeze the pot in different directions to loosen everything up. Grip your plant gently as close to the soil as possible and see if you can ease it out of the pot, try a little wiggle if it's tight. If you really can't get it out and don't mind losing the pot, you can always cut it open to release your plant.
A child repotting a plant
2. Remove old soil and loosen roots gently
The difficulty of this will vary with different potting mediums. I have given up on trying to detangle moss from delicate plant roots! They break more often than they separate and the extra moss won't do them any harm, so into the new pot it goes.
It can be hard to get the soil off and loosen the roots if the soil is really dry. But it's best not to repot straight after watering, as it might be messy! Wait a few days before repotting.
3. Place plant in a new pot with fresh soil.
The first two steps were the easy bit. Step three is the crucial part, and it's actually two-steps. Sorry.
Firstly, your new pot shouldn't be massively larger than the old pot and please please make sure its got holes in the bottom.
Have a look at your roots and judge the pot size accordingly. Does it look like they will have enough space in there to do their thing? You don't want to go too large too soon as it can overwhelm a small plant.
If you can't easily fit the roots into just over half the pot, consider a larger one. Remember, your plant might like a pot on the tighter side depending on what it is.
Repotting fiddle leaf fig tree in big modern pot. Ficus lyrata leaves and pot, drainage,garden tools, soil on wooden floor.
Secondly soil, or potting medium. By this, I mean soil plus some other stuff.
Many beginners struggle with information overload regarding soil and what to mix into it, and it can all be a bit confusing. But stick with me because what you are putting your plant roots into is the most important part of repotting.

A simple mix

For simplicity, I'm going to recommend just adding some perlite or moss, dependent on what you're growing! Adding moss to typical potting soil increases how much water the potting medium will hold.
This is good for plants that like more moisture, like Prayer Plants:
A pot of prayer plants
Adding perlite to soil increases the drainage. That is, how fast water drains through to the holes in the bottom of the pot.
It takes an expert hand to water so precisely as to avoid overflow, so always use pots with drainage holes. It can then be placed inside a pretty decorative pot without holes.
I can't dive too far into soil here as there's so much to explore! But I would strongly recommend doing some research on your exact houseplants and what kind of conditions they like.
Look into their natural environment and where they originate from, how other people are growing the same plant in their home and experiment with your soil mixes.
If you wanted to learn more about how soil works, have a browse of these:

A bit more about plant parts

Plants consist of leaves, stems and roots (unless they're flowering!) and they divide their growing energy between these three parts. The stems and leaves of houseplants can be called the foliage, with the roots often overlooked, hidden in the pot.

Why roots are important

Inside plant pots, there's just as much exciting growth happening as outside. Roots are a key part of plants, and there are many specialised adaptions to the basic root structure. For example, some roots (storage roots) are adapted to store water or food, like Carrots and Beetroots!
There are also aerial roots. These are roots that grow entirely above the soil and are adapted to absorb water and nutrients directly from the air. Plants with these kinds of roots are called epiphytes, and some plants can produce normal soil roots and air roots, such as species of Ficus.
Mangroves have very different aerial roots, specialised to allow them to grow in wet, salty coastal environments. Their aerial roots grow up above the water and are adapted to provide oxygen through airflow. Mangroves also produce structural roots, called prop roots, that help support the plants.

What do roots do?

The main functions of most roots are to anchor the plant in place and allow plants to absorb water and nutrients from the soil. The often-overlooked factor is air. Plant roots need to "breathe" similar to how we humans do, and by this, I mean respire.

Respiration

Respiration is a fundamental biochemical process that produces energy. It occurs in our cells, in animal cells and plant cells. In respiration, water, carbon dioxide and energy (in the form of ATP) are released from oxygen and glucose.
A close up of text on a white background
In respiration, oxygen (O₂) and glucose (C₆H₁₂O₆) are converted into water (H₂O), carbon dioxide (CO₂) and energy in the form of ATP
Respiration is essentially the opposite of photosynthesis, and you can read more about that, why plants need water and why plants are green here:
Best of luck with repotting your plants! If you have any more repotting questions, feel free to tag me on Candide and I can try to help.
Browse more houseplants here:
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