Repotting houseplants — when and how, step by step

Repotting is not cosmetic — it is a reset of the conditions the roots live in. Done in time and correctly, it gives the plant fresh mix, room to grow and working drainage. Done badly — too soon, into a pot that is too large, or at the wrong time of year — it does more harm than good. This guide shows when you really need to repot and how to do it step by step.

When to repot — signs, not the calendar

The plant itself shows you the pot has become too tight:

• Roots come out of the drainage holes at the bottom or push up at the surface of the mix.
• Water runs straight through almost immediately after watering — the root ball is now mostly roots, with too little mix to hold moisture.
• Growth has stalled despite light and feeding; once you slide the plant out, you see the roots wound in a dense spiral around the walls (rootbound).

The best time is spring — the start of the growing season, when the plant regenerates roots fastest. Avoid repotting a plant in full bloom (such as a moth orchid in flower) and avoid forced repotting in autumn and winter, when growth slows anyway.

Not every plant likes frequent repotting. The snake plant and ZZ plant grow slowly and actually prefer a snug pot — repot them every 2-3 years, not every year. The weeping fig copes badly with change and may drop some of its leaves after repotting — only do it when you really have to.

How much bigger the pot

An easy rule to remember: a new pot 2-4 cm larger in diameter than the current one (for large specimens in tubs, one size up). Don’t jump several sizes at once. A pot that is too large is the most common beginner’s mistake: the excess mix around a small root ball holds water for a long time, the roots can’t take it up fast enough and they rot — a direct route to root rot. Better to repot more often into a slightly bigger pot than once “for good measure”.

The pot must have drainage holes. A decorative cover pot without holes is fine, but the plant should sit in an inner pot with drainage, and excess water must be poured out of the cover pot.

Potting mix and drainage

Fresh mix is half the battle. For most foliage plants a good all-purpose mix is enough; for succulents and the snake plant — free-draining, with added perlite or sand; for the orchid — a special bark-based mix, not ordinary soil. Real drainage comes from a free-draining mix and holes in the base, not from a layer of stones or clay pebbles at the bottom — a popular myth that does not improve drainage and sometimes makes it worse.

Step by step

1. Water the plant the day before. A moist root ball slides out more easily and damages the roots less.
2. Take the plant out. Tip the pot, hold the base and slide it out gently; tapping the walls helps. Don’t pull on the stem.
3. Inspect the roots. Healthy ones are pale and firm. Dark, soft, foul-smelling roots — cut them off with a clean tool. Gently loosen a dense, spiralled ball with your fingers so the roots move out into the new mix.
4. Put some mix in the bottom of the new pot and set the plant so the base sits at the same depth as before — no deeper, because a buried stem rots.
5. Add mix around the sides, pressing lightly, but without compacting it solid. Leave about 1-2 cm below the rim for watering.
6. Water moderately to settle the mix around the roots.

Care after repotting

Repotting is stressful — the first weeks are recovery, not a time for “feeding up”:

• Put the plant in brighter shade, away from harsh sun, for a week or two. Less light means less evaporation while the roots recover.
• Hold off on feeding for 4-6 weeks. Fresh mix has a store of nutrients, and fertiliser on damaged roots will scorch them.
• Water carefully. A fresh root ball with a small root system is easily overwatered — check the moisture with your finger and only water once the top layer has dried out (see how to water houseplants).
• Some leaves drooping for a few days is normal. The Swiss cheese plant or peace lily usually perk up quickly once the roots take hold of the new mix.

Common mistakes

• A pot that is too large → overwatering and root rot. The biggest and most common mistake.
• Feeding straight after repotting → scorched, weakened roots.
• Planting too deep → a stem rotting at the base.
• Repotting when there is no need → unnecessary stress; slow-growing species prefer to be snug.
• Compacting the mix solid → no air at the roots and poorer drainage.