How to repot houseplants indoors: a step-by-step guide

Remove your plant from its pot and take a good look at the roots. “If the roots have become pot-bound and coiled around themselves, it’s a good idea to tease them out so they can penetrate the fresh compost you’re planting them into,” says Palmer. She recommends doing this gently with your hands so as not to damage the roots.
Take a new, larger pot that has drainage holes. “This could be a plastic inner pot that you’ll put into a more aesthetically pleasing ceramic one, or a metal pot that you’ve punched a few holes in, with something underneath to catch excess water,” says Palmer.
Next, Palmer recommends adding “a tiny bit of gravel or a few pebbles at the bottom of the pot to help with drainage. It’s important that your roots aren’t sitting in water.”
After that, take your plant, put it into the new pot and surround it with fresh houseplant compost, leaving a gap between the top of the soil and the top of the pot if possible. “This will extend the lifespan of the new pot,” says Palmer. “When you notice the soil depleting, you can fill this space with new compost to give your plant extra room to grow.”
In the meantime, Palmer suggests filling this gap with another material. “Empty space isn’t very nice to look at, so you can top up the pot with gravel or hydroleca (clay granules that absorb water and release it over time).”
Water your plant after repotting and wait with bated breath for it to flourish in its new, roomy surroundings. Phew. Your plant parenting guilt is assuaged…

How to repot a houseplant when you don’t have a garden (without making a mess)