How to repot a houseplant without killing it

2026-07-01

Repotting is one of the most valuable things you can do for a houseplant, yet it is also one of the most misunderstood. Done at the wrong time or in the wrong way, it can set a plant back for months. Done well, it gives roots fresh space and nutrients, and can transform a struggling plant into a thriving one. The good news is that once you understand a few key principles, the process becomes straightforward and genuinely satisfying.

How to tell when repotting is actually needed

The clearest sign is roots escaping through the drainage holes or circling visibly around the surface of the compost. You might also notice the plant drying out far faster than it used to, or growth slowing noticeably in spring despite good light and feeding. Gently tip the rootball out and have a look: if roots are tightly packed and you can barely see any compost, it is time to repot. However, do not repot on a schedule or out of habit. Many plants, including peace lilies and spider plants, actually flower better when slightly pot-bound, so wait for the evidence before you act.

Timing: when to repot for the best results

Spring is almost always the best time, ideally between March and May when day length is increasing and the plant is entering active growth. Roots establish far more quickly in warm compost, and the plant has the whole growing season ahead of it to recover and settle in. Avoid repotting in winter when most houseplants are resting, as fresh compost around inactive roots sits wet for too long and risks rotting them. If a plant is in obvious distress, such as being severely root-bound or having waterlogged, compacted compost, it is fine to repot at any time of year, but keep it somewhere warm and bright afterwards and ease off watering for a week or two.

Choosing the right pot and compost

Go up just one pot size, typically 2 to 5 cm wider in diameter than the current pot. A pot that is too large holds excess moisture around the roots, which encourages rot rather than growth. Make sure the new pot has drainage holes; if you love the look of a decorative pot without holes, use it as a cachepot and keep the plant in a plain nursery pot inside it. For compost, match it to the plant: a peat-free multi-purpose compost suits most tropical foliage plants, while cacti and succulents need a gritty, fast-draining mix (add around 30 to 50 per cent perlite or coarse horticultural grit to standard compost). Orchids need specialist bark-based orchid compost, and ericaceous plants such as gardenias need acidic compost. Using the wrong compost type is one of the most common repotting mistakes.

The repotting process, step by step

Water the plant an hour or two before you start so the rootball holds together without crumbling. Cover the drainage hole with a small piece of mesh or a crock (a broken piece of pot) to stop compost washing out, then add a layer of fresh compost to the base of the new pot. Ease the plant from its old pot by squeezing the sides if it is plastic, or running a knife around the inside edge if it is ceramic. Gently tease apart any tightly circling roots with your fingers, and trim away any that are black, mushy, or very dry and dead using clean scissors or secateurs. Set the plant in the new pot so the top of the rootball sits roughly 2 to 3 cm below the rim, which leaves room for watering. Fill in around the sides with fresh compost, pressing it down lightly but firmly to remove large air pockets, then water gently to settle everything in.

Aftercare: getting your plant through the transition

Place the plant back in its usual spot rather than moving it somewhere new at the same time; combined stresses make recovery harder. Hold off on feeding for at least four to six weeks, as fresh compost already contains nutrients and feeding too soon can scorch tender new roots. Water only when the top couple of centimetres of compost feel dry, since over-watering during this adjustment period is the single most common cause of post-repotting decline. Some leaf drop or temporary wilting is normal and not cause for alarm; give the plant a couple of weeks and it should perk up noticeably as roots begin to explore the new compost.

When you cannot or should not go bigger

Large plants such as mature fiddle-leaf figs or olive trees eventually reach a pot size that is simply impractical to increase further. In this case, top-dress instead: carefully scrape away the top 5 to 8 cm of old compost without disturbing the roots, and replace it with fresh compost mixed with a slow-release granular fertiliser. This refreshes the growing medium and gives the plant a nutrient boost without the upheaval of a full repot. It is a surprisingly effective technique and worth doing every spring for any large specimen that has outgrown the process.