Repotting means moving a plant into a bigger container with fresh mix so its roots have somewhere to go. Most owners run it on a yearly habit and get it wrong in both directions, too early on the slow growers and far too late on the fast ones. Here's the root test that settles timing, the size step to take, the 6 steps in order, and the months that suit the job in the UAE.
The root test that settles timing
Tip the plant out and read the outside of the root ball. Three states tell you what to do. Soil visible with roots scattered through it means leave it alone, roots circling with mix still between them means repot next season, and a solid mat with no mix showing means repot now.
This beats a calendar because plants fill a pot at wildly different speeds. A pothos or a spider plant can bind a 15 cm pot in 8 months. A ZZ plant can sit in the same pot for 4 years and still show mix on the outside of the ball. One yearly schedule disturbs the second plant for nothing and starves the first.
To run the test, water the day before, lay the pot on its side, hold the stem base between two fingers and slide the pot off. If it won't slide, run a blunt knife around the inside wall first. Look, then put it straight back if the answer is not now.
It takes under a minute and does no harm.
Four secondary signs support the test without replacing it: roots pushing out of the drainage holes, water running straight through in under 5 seconds, mix shrinking away from the pot wall, and a plant drying out twice as fast as it did last year. Treat any of them as a prompt to tip the plant out and look.
Choosing the pot size
Step up 2 cm to 5 cm in diameter for pots under 20 cm, and 5 cm to 8 cm for anything above that. Never jump more than 8 cm in one move. The new pot needs a drainage hole, and for most foliage plants its depth should roughly match its width.
The reason for the small step is water rather than space. Mix with no roots in it holds water and nothing draws it out, so an oversized pot keeps a wet zone around a small root ball for days. That's the fastest route to rot, and it's why a plant moved from a 15 cm pot straight into a 30 cm one usually declines instead of surging.
Material shifts the watering interval more than diameter does. Unglazed terracotta breathes and dries the mix from every side, which suits plants that hate wet feet. Glazed ceramic and plastic hold moisture longer, which suits thirsty species and rooms where the AC runs all day. Pick the material first.
Weight matters for anything over a metre tall in a Dubai apartment, where plants get shifted for cleaning and window work. A fibreglass or composite planter at that size weighs a fraction of what concrete does. The pots and planters collection lists diameters and materials together, which makes the exact 2 cm step easy to find rather than guessing from a photograph.
The 6 steps
Repotting runs in 6 steps. Water the plant a day ahead, take it out of the old pot, tease the outer roots free, part fill the new pot, set the plant at its original depth, then backfill and settle it with water. Work in that order.
- Water 24 hours ahead. A hydrated root ball holds together and slides out cleanly, while a dry one crumbles and tears fine roots.
- Lay the pot on its side, support the stem base, and slide the pot off. Never pull a plant out by its stem.
- Loosen the outer 1 cm of the ball with your fingers and cut any root that circles the base. Circling roots carry on circling and eventually tighten around the stem.
- Add enough fresh mix that the top of the root ball will sit 2 cm below the rim. Those 2 cm are the watering reservoir.
- Set the crown at exactly the height it sat before. Burying it rots the stem and raising it leaves roots exposed.
- Fill around the ball, then water slowly until it drains. Water settles mix into the gaps, whereas pressing it down by hand compacts it and drives out the air roots need.
Don't add gravel or broken pottery to the base. It raises the saturated zone in the pot instead of draining it, which is the opposite of what it is meant to do.
When to repot in the UAE
Repot between October and May. That's the UAE growing season, when a disturbed plant can push new roots into fresh mix inside 3 weeks. June to September is the period to avoid, with heat holding most indoor and outdoor plants at minimum activity.
Two exceptions override the calendar. A plant with root rot, identified by black soft roots and a sour smell, gets repotted the day it's found, whatever the month. A plant just brought home gets left alone for 3 to 4 weeks first, so it faces one change at a time.
Hold back fertiliser for 6 weeks afterwards. Fresh mix already carries nutrients, and feeding cut roots pushes salt against tissue that's trying to heal.
FAQ
Repotting questions tend to arrive at the wrong end of the job, once a plant has already been moved and has sulked for a fortnight. These three cover the timing decision, the size step to take, and what to do with the roots on the way across.
When should an indoor plant be repotted?
When the root ball comes out as a solid mat with no mix showing on the outside. Check by sliding the plant out of its pot rather than working to a yearly schedule, and do the job between October and May.
What size pot should you move up to?
Up 2 cm to 5 cm in diameter for pots under 20 cm, and 5 cm to 8 cm for larger ones. A bigger jump leaves wet mix with no roots in it, and that causes rot rather than faster growth.
Should the roots be loosened first?
Yes. Loosen the outer 1 cm of the ball with your fingers and cut through any root circling the base. Roots that have learned to circle carry on doing it in the new pot and tighten around the stem over the years.