Repotting means moving a plant to a new container and renewing its compost. You do it when the roots have run out of room, not when you no longer like the planter. The RHS recommends going up only one pot size each time. With the right method, the plant resumes growth within two or three weeks. Without it, the plant loses fine roots and stalls for several months. This guide uses seven steps, specific quantities and the +2/+4 cm diameter rule. The cache-pots in the planters collection come in at the final step.
Materials and items you need
Everything fits on an 80 × 60 cm table. Gather it all before taking the plant out of its pot. Exposed roots lose moisture within minutes.
- A new nursery pot with drainage holes, 2 to 4 cm wider than the current one.
- A decorative planter or cache-pot, 2 to 3 cm wider than the new nursery pot.
- Multi-purpose compost: 1.5 to 2 litres for every 14 cm of pot diameter.
- Clay pebbles or fine gravel for a 2 cm layer at the bottom of the pot.
- A rigid saucer, 1 cm smaller in diameter than the inside of the cache-pot.
- Clean pruning scissors and 70% alcohol to disinfect them.
- Gardening gloves and a thin stick about 25 cm long.
- A 0.5 litre watering can with a narrow spout.
- Paper or plastic to cover 1 m² of floor.
The compost and drainage always go inside the nursery pot. The decorative cache-pot stays empty inside except for the saucer. Fluxenna planters are PLA bioplastic with a matt finish.
Step 1: Check that the plant needs repotting
Three signs show that the pot has become too small. The first is roots poking out of the drainage holes. The second is water running through the compost in less than five seconds. The third is a plant that dries out every two days on its usual watering. If none of these appear, put off the change. The calendar matters here too. The right window runs from late winter to early spring. Spain's AEMET issues heat warnings every summer, and above 30 °C the roots suffer.
Trick. Lift the pot. If it feels very light just after watering, the compost is exhausted.
Trick. Count the years. An average houseplant needs a change every 18 to 24 months.
Step 2: Choose the diameter with the +2/+4 cm rule
The most costly mistake is made at this point. Measure the top diameter of the current pot with a tape measure. Add 2 cm for a slow-growing plant and 4 cm for a vigorous one. A 12 cm pot moves up to 14 or 16 cm, never to 20. A bigger jump leaves compost without roots, which holds water and rots. Then choose the cache-pot: 2 to 3 cm wider than the new nursery pot. With a 16 cm nursery pot, the decorative planter is 18 to 19 cm. The catalogue covers diameters from 10 to 28 cm.
Trick. Measure inside the rim, not outside; there is about 1 cm of difference.
Trick. If you are torn between two sizes, choose the smaller one. Too much compost is a more frequent problem than too little.
This guide by plant type and style breaks the criteria down species by species.
Step 3: Water 24 hours before and prepare your workspace
The root ball comes out in one piece if the compost is moist, neither soaked nor dry. Water the plant the day before with about 0.3 litres of water. Cover 1 m² of floor with paper and keep the materials within reach. Fill the bottom of the new pot with 2 cm of clay pebbles. Add compost up to a third of the height and press lightly. That base sets the final height of the root ball. Multi-purpose compost suits most houseplants. Succulents need a mix with sand and orchids need bark.
Trick. Bring the water to room temperature. Cold tap water slows the roots down.
Trick. Prepare the new pot before taking the plant out, not afterwards.
For diameters of 10 to 14 cm, this guide to small planters details the proportions.
Step 4: Remove the root ball without pulling the stem
Never pull on the stem. Hold the plant with your open hand on the surface of the compost. With your other hand, turn the pot over and tap the rim against the table. If it does not give, run a thin knife around the inside wall of the pot. Soft plastic nursery pots can be squeezed by hand to release the root ball. A rigid pot sometimes has to be cut, and that is better than breaking roots. The root ball should come out as a block, with the compost held together by the roots. If it crumbles completely, the plant had not been in there for long.
Trick. Hold the stem between your index and middle fingers, without squeezing.
Trick. Work over a soft surface. A 30 cm drop splits the root ball.
Step 5: Loosen the roots and remove damaged parts
A plant with circling roots does not grow even if it changes pot. Loosen the bottom third of the root ball with your fingers. Separate the roots that circle around following the wall of the old pot. With clean scissors, cut off brown, soft or smelly roots. Healthy roots are white or pale and firm to the touch. Do not remove more than a third of the root volume in a single session. Shake off the old compost only if you are going to renew all of it.
Trick. Disinfect the scissors with 70% alcohol between plants.
Trick. With very pot-bound roots, make four vertical 2 cm cuts down the side.
Trimmed branches and leaves dry well in a tall container. The designer decorative vases collection covers that format. More cache-pot silhouettes in this selection of decorative planters.
Step 6: Fill the pot and adjust the height of the collar
Place the root ball centred on the compost base. The collar of the plant should sit 2 cm below the rim of the pot. That margin stops water from overflowing when you water. Fill the gap around the edge with compost in two or three goes. With the thin stick, push the compost down without compacting it. Compost that is packed too tightly leaves the roots without air. Check that the plant is upright by looking at it from two different sides. Never cover the collar with compost: it is the fast track to rot.
Trick. Tap the pot against the table twice. The compost settles by itself.
Trick. Leave 1 cm of margin below the collar; the compost sinks after the first watering.
Step 7: Place the nursery pot inside the planter and wait two weeks
This is where the decorative planter comes in. Fluxenna planters are cache-pots: they wrap around the nursery pot and are not declared watertight. Water first outside, in the sink, with 0.5 litres of water. Wait for it to stop dripping, between 10 and 20 minutes. Put the saucer inside the cache-pot and the drained nursery pot on top. The rhythmic geometry fluted pot starts at €9.99 in tabletop diameters. If you water irregularly, the fluted cylindrical self-watering planter starts at €4.99 and has a built-in reservoir.
Trick. Do not feed during the first month. Fresh compost already contains nutrients.
Trick. Write the date on a label. The next change is due in 18 months.
Five common mistakes
1. Jumping two or three sizes at once. Compost without roots holds water and ends up rotting the root ball. Solution: apply the +2/+4 cm rule and repeat the change after 18 months.
2. Putting compost inside the decorative planter. The cache-pot has no drainage and water stagnates at the bottom. Solution: compost always goes in the nursery pot.
3. Burying the plant's collar. The base of the stem stays wet and rot appears within a few weeks. Solution: leave the collar 2 cm below the rim and visible.
4. Repotting in hot weather or in full bloom. The plant spends its energy on flowers and does not rebuild roots. Solution: wait until late winter or early spring.
5. Watering inside the cache-pot without a saucer. Excess water collects between the nursery pot and the decorative wall. Solution: water in the sink and return the plant once drained.
Reference table by plant type
The table starts from the most common nursery pot for each species. According to industry data, the best-selling indoor nursery pot measures 12 to 14 cm. Formats with an engraved name are in the personalised planters collection. Houzz has been recording the rise of layered lighting in the living room. If the plant ends up next to a lamp, repeat the matt finish. The formats are in the designer table lamps collection.
| Plant | Current pot | New pot | Cache-pot | Approximate compost |
|---|---|---|---|---|
| Pothos | 12 cm | 14-16 cm | 16-18 cm | 1.5 l multi-purpose |
| Snake plant | 14 cm | 16 cm | 18-19 cm | 1.8 l multi-purpose with sand |
| ZZ plant | 14 cm | 16-18 cm | 19-21 cm | 2 l multi-purpose |
| Young monstera | 17 cm | 20-21 cm | 23-24 cm | 3 l multi-purpose |
| Young ficus lyrata | 19 cm | 22-23 cm | 25-26 cm | 4 l multi-purpose |
| Calathea | 12 cm | 14 cm | 16-17 cm | 1.5 l with coir |
| Peace lily | 14 cm | 16-18 cm | 19-20 cm | 2 l multi-purpose |
| Fern | 12 cm | 14-16 cm | 17-18 cm | 1.8 l with coir |
| Succulent | 8 cm | 10 cm | 12 cm | 0.5 l with sand |
| Small cactus | 8 cm | 10 cm | 12 cm | 0.5 l mineral |
| Aloe vera | 12 cm | 14 cm | 16 cm | 1.2 l with sand |
| Basil | 12 cm | 14 cm | 16 cm | 1.5 l multi-purpose |
Cache-pot diameters add 2 to 3 cm to the new nursery pot. The catalogue goes up to 28 cm in diameter. PLA bioplastic meets the EN 13432 standard for industrial compostability; it is not compostable in a home compost bin.
Frequently asked questions
How often should you repot a houseplant?
An average houseplant needs repotting every 18 to 24 months. Before that, there are three signs. Roots poking out of the drainage holes. Water running through the compost in less than five seconds. Watering that lasts only two days. With just one sign, it is worth checking the root ball.
How much diameter should you add when changing pot?
Add 2 cm of diameter for a slow-growing plant and 4 cm for a vigorous one. A 12 cm pot moves up to 14 or 16 cm. The RHS recommends going up only one size each time. A bigger jump leaves compost without roots, which holds water.
What do you fill a decorative planter with?
Nothing. A Fluxenna planter is a cache-pot and does not take compost inside. The compost and drainage go in the nursery pot, which does have holes. Inside the cache-pot there is only a rigid saucer with the drained nursery pot on top.
Can you repot in summer?
Better not. The right window runs from late winter to early spring. Spain's AEMET issues heat warnings every summer, and above 30 °C the roots suffer. If the plant cannot wait until March, repot at dawn and keep it in shade for two weeks.
When do you water after repotting?
Water straight after repotting, with 0.5 litres and outside the cache-pot. Wait 10 to 20 minutes for it to stop dripping. The second watering comes when the top 3 cm of compost are dry. Do not feed during the first month.
To sum up
Repotting well depends on two decisions, not on strength. The first is the diameter: add 2 or 4 cm and never more. The second is the division of roles. The nursery pot drains and holds the compost; the cache-pot decorates and does not get wet inside. Spain's Ministry of Agriculture has been recording the steady share of ornamental plants in household spending. Diameters from 10 to 28 cm are in the planters collection.
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