Gadenin日本語Get the appWhen it actually needs a new pot
These plants are in no hurry. A pot-bound Rhipsalis flowers and grows perfectly well, and the commonest repotting mistake is doing it too often into a container far too big. Every two or three years is normal, and a big established basket can go longer if you top-dress instead.
Repot when you see roots coming out of the drainage holes in quantity, when water runs straight through without wetting anything, when the plant needs water every two or three days in warm weather, or when the mix has broken down into a dark airless sludge. Bark composts collapse over time, and old spent mix suffocates fine roots even in a pot that is not full.
Do it in the warm months while the plant is in active growth. Roots cut or disturbed then knit into new compost in a few weeks. The same work done in a cold room means damaged roots sitting in wet mix for months, which is how a healthy plant is lost to rot over winter.
The mix: bark, not grit
This is where the desert cactus advice does real damage. A gritty, sandy, low-organic cactus compost drains beautifully but holds almost no moisture and no organic matter, and a forest cactus rooted in leaf litter simply starves and dries in it.
What you want is something close to a fine orchid mix: open enough that water runs through in seconds and air reaches the roots, but with enough bark and organic matter to stay lightly damp for days. It should feel chunky and springy in the hand, never dense and muddy.
| Component | Proportion | What it does |
|---|---|---|
| Fine to medium orchid bark | About one third | Creates the air pockets and keeps the mix open for years |
| Peat-free houseplant compost or coir | About one third | Holds the moisture and nutrients the fine roots live on |
| Perlite or pumice | About one quarter | Keeps drainage fast without adding weight |
| Coarse horticultural sand or fine gravel | A small handful | Adds a little ballast to a top-heavy hanging pot |
| Worm castings or leaf mold | A small handful | Slow, mild feeding of the kind it gets in a tree fork |
If you would rather buy than blend, an orchid or bromeliad mix loosened with a third of ordinary houseplant compost is much closer to right than any bag labeled cactus and succulent.
Pot size and pot type
Go up one size only, an inch or two (3 to 5 cm) more across than the old pot. An oversized pot holds a mass of wet compost that no roots reach, and that unused wet zone is where rot starts. A slightly tight pot dries evenly and suits the plant fine.
Drainage holes are not negotiable. A decorative pot with no hole is acceptable only as an outer cover, with the plant in a plastic liner you can lift out to water and drain.
For hanging plants, weight matters in both directions. Plastic is light on the ceiling hook and holds moisture longer between waterings; terracotta breathes and dries faster, which forgives a heavy hand with the watering can but doubles the weight hanging from one fixing. Choose according to which mistake you tend to make.
Doing the job without breaking the plant
The stems detach at the joints under very little force, so the handling matters as much as the compost. Work on a table with room to lay the fall of stems out flat, and support the plant by the root ball rather than the stems throughout.
- Water lightly a day ahead Slightly damp compost holds together and slides out cleanly. Bone-dry mix crumbles away and tears the fine roots as it goes.
- Gather the stems before you lift Loosely bundle the trailing stems together with a soft tie or lay them over your forearm. Free-hanging stems catch on everything and snap.
- Ease it out and inspect the roots Squeeze a plastic pot or run a knife around a rigid one. Healthy roots are pale and firm. Cut away anything brown, hollow or mushy with clean scissors.
- Tease off only the spent mix Crumble away the loose collapsed compost from the outside and the top. Leave the core root ball intact; full bare-rooting sets the plant back for months for no benefit.
- Set it at the same depth Put an inch (2.5 cm) of fresh mix in the base, sit the plant so the crown is at the same height as before, and fill around the sides. Burying the crown deeper is a direct route to rot.
- Firm gently, then leave it dry for a few days Tap the pot to settle the mix rather than pressing it down hard. Wait three to five days before the first watering so any cut roots can seal over.
The first month afterwards, and the years between
Hang it back in its usual place, but somewhere a little shadier than normal for two or three weeks, and do not feed at all for six to eight weeks. Fresh compost carries enough nutrition, and fertilizer on freshly cut roots burns them. Expect no visible new growth for a month; that is normal and not a sign of failure.
Watch the watering closely for that first month. A new pot of fresh open mix holds moisture differently from the old one, and the same routine you used before will usually now be too wet. Go back to the finger test until you have relearned the rhythm.
In the years between repottings, top-dress instead. Scrape off the top inch (2.5 cm) of tired compost each warm season and replace it with fresh mix. That renews the surface and feeds the plant without ever disturbing the root ball.
Note the date, the pot size and the mix you used on a label pushed into the compost or in your records. When the plant thrives or sulks two years later, that one line tells you what to repeat and what to change.