Is your green buddy due an upgrade?
After a year or two in the same pot, plants exhaust their soil's nutrients and need repotting. If your plant has a strong enough root structure, you can also move him to a bigger planter and decorative pot.
Growing season is the best time to transplant your green buddies, as they'll replace any damaged roots quickly and spread out to fit their new planters!
When should you repot plants?
Spring is the best time to repot your houseplants. Though they live in doors, houseplants still respond to seasonal changes.
You may have noticed that your plants have needed watering less frequently when it’s cold and dark. During winter, growth slows right down, and some plants even become dormant, meaning they require less water and feeding. It’s a bad idea to repot your plants at this time because the upset caused by repotting could cause plants to fail in itself, and they’re unlikely to grow into their new planter, which makes them extra vulnerable to root rot.
Now, as we move closer to the Summer solstice, longer, warmer days will push your plants into their active growing phase.
This means it’s time to buy fertiliser and think about repotting your plants!
Plants need their soil refreshing once every year to two years. After this time, your plant will have used up all the nutrients in the soil and you’ll need to give it some nourishment.
How do I know if my plant is ready to be repotted?
It's important to note that most varieties won't suffer too much from being root bound, and some varieties even like it - like Hoyas and Ponytail Palms. Finding the odd root poking out of your plant pot should not be cause for concern.
Plus, any environmental upset can cause your plant to panic, so you should not re-pot unnecessarily.
If you see a combination of these signs, it's a good indication that it's time to re-pot:
1. Roots are growing through the drainage hole at the bottom of the growing pot.
2. Roots are pushing the plant up, out of the pot.
3. Plant is extremely top heavy, and falls over easily (for some varieties this may be normal).
4. Plant dries out more quickly than usual, requiring more frequent waterings.
5. Noticeable salt and mineral build up on the plant or planter.
6. Yellowing, or off-colour, leaves.
Read more answers to repotting FAQs here. 
How to repot indoor plants
You will need:
Soil appropriate for your plants (ideally cactus soil for succulents and desert-dwellers) and well-draining soil for most other houseplants.
Growing pots approximately 3cm bigger in diameter than those of the plants your repotting (if you’re looking to size-up your houseplant).
Water.
Optional:
A trowel or shovel (though we prefer using fingers!)
Sharp plant shears or scissors (if you want to use this opportunity to prune your plant).
Step 1.
Take your new growing pot and fill it a third of the way with slightly moistened soil. Give it a gentle pat but no need to pack it tightly.
Step 2.
Gently pull your plant from its growing pot by tilting it at an angle and letting it fall into your hand.
Step 3.
Using your fingers, very carefully brush away the old soil from the plant’s roots and trim any weak-looking long roots.
Step 4.
Gently place your plant, less most of its old soil, on top of the layer you’ve made, and lightly pack soil around the plant, leaving an inch of space at the top so your plant can breathe.
Step 5.
Find a snazzy new decorative pot to place your newly repotted friend in!