Taken from my Februarys copy of the RHS Garden and worded in my simple English.

Do you have any permanent container plants? Anything on your patio? If so then its a good time to re pot them. This is to replenish the used up soil they have been living in for the past year or so. Plants like humans need food including nutrients amongst other things to survive which is why when they have been sat in the same soil for over a year they want new soil or compost which has fresh nutrients in. Changing the pot is also important as most plants will have out grown their pots and so need to go into the next size up. I feel like that after mums Christmas dinner!

First things first decide does your plant need to go into a bigger pot, some plants are already to big for their pots but its impractical to put them into a new pot, therefore simply take the plant out, carefully i might add, i have smashed a few pots by accident here and then had to find replacement pots anyway. If the plant has really grown into the pot, i’ve seen mint or Mentha become completely pot bound and it taking two strong determined ladies and a very sharp kitchen knife to overcome its stretched pot. All three of us ended up on the floor with a smashed pot but some very lush juicy roots to show for our efforts. Some great cutting material. Incidentally this was done in late summer autumn time.

So if your plant needs a bigger pot because it’s pot bound and it’s roots have no where else to grow i would cut off the bottom roots roughly a third of the root ball, some its less, if it looks thick and pot bound do a third if not only take off a small amount. Then in your new pot place some broken pots or what ever you use for aiding drainage at the bottom of the pot and add a bit of compost relevant to the type of plant your re-potting, eg use Ericaceous for acid loving plants. Then place your plant the right way up and fill the spaces with compost. Some people add some bone meal into their pots before adding the plants, I tend to just use some slow releasing multi purpose plant food, unless the plants needs something specific.

If you can’t get it into a new pot then do the same as above but there will be less new compost going into the pot. If you can tease out the roots of the plant and remove some of the existing soil that would be beneficial but you can only practically do that with some plants.

Place your pot where you want it to sit and wait for the plant to awaken.