Do you have permanent pot plants that look like they might be in need of a boost? You might be noticing yellowing leaves, or simply that the plant hasn’t grown as you’d hoped or expected. If so, then now is a good time to consider re-potting it.
Containerised plants sitting in the same compost for more than a two or three years are likely to be needing extra nutrients that (unlike their friends in the flower bed) they cannot access. You can of course provide this with a liquid fertiliser, once the danger of frost has passed, but new compost is a better solution, not only improving the soil structure, but also giving you the opportunity to inspect the roots of the plant and give it a larger pot if necessary.
Begin with long-term plantings as they are always in most need. Remove each plant from its container. If the roots are starting to spiral around the outside of the root-ball then it’s time for a larger pot; if not, then remove old excess soil and replant in the original container.
Ensure that the hole in the bottom of the container doesn’t get blocked up by compost by putting a crock over it, and fill with new compost. I use John Innes number 2 for pretty much everything that isn’t temporary. Gently tease out the roots by giving the root-ball a good rub, and re-plant carefully, making very sure that you’re getting the soil properly into the gap between the sides of the pot and the root-ball. This is time consuming work, so if you really cannot face it then top-dressing is an acceptable interim measure until next year, removing the top two inches of soil and replacing it with new. Even this small gesture will be rewarded with happier, revitalised plants.