Gadenin日本語Get the appTelling whether it needs repotting
The clearest sign is that water runs straight through and out of the bottom without the compost getting wet. The roots have filled the pot and the water has found channels rather than soil, so the plant is thirsty however much you pour.
Roots pushing out of the drainage holes, and new leaves coming smaller than the old ones despite good light, point the same way.
Feeding a pot bound plant does not help. There is no compost around the roots to hold it, so the concentration rises and damages them.
Repot in late spring or early summer
Repotting breaks roots, and the plant has to replace them, which only happens while it is warm and growing. The season matters more than how pot bound it looks.
| Season | Repot? | Why |
|---|---|---|
| Late spring to midsummer | Best | Warm enough for cut roots to regrow quickly |
| Late summer | On a cool day | Working in real heat costs the plant more |
| Early autumn | Only potting up | Move it up without disturbing the rootball |
| Late autumn to mid spring | Avoid | Roots do not move and cut surfaces die back |
One size up
Move up a single pot size. A much larger pot leaves a mass of compost with no roots in it, and that compost stays wet, which is how a healthy plant ends up with root rot.
| Current pot | Next pot | The plant |
|---|---|---|
| 3.5 in (9 cm) | 4.5 in (12 cm) | A cutting about a year old |
| 4.5 in (12 cm) | 5.5 in (15 cm) | Vines 12 to 20 in (30 to 50 cm) long |
| 5.5 in (15 cm) | 7 in (18 cm) | Vines around 3 ft (1 m) |
| 7 in (18 cm) | 8 to 10 in (21 to 24 cm) | A large plant on a pole |
You can also stay in the same pot and replace the compost. For a small plant on a desk, that keeps it the same size indefinitely.
Compost and how to do it
Any free draining houseplant compost works. Add perlite or bark if it holds too much water for how often you like to water.
Wet the compost before you use it. Dry compost repels water, so a plant potted into it can be watered and still not have wet roots.
Growing in water or in compost
Pothos will live indefinitely in water or in a semi-hydroponic setup, and the trade-offs are consistent enough to choose between deliberately.
| Aspect | In compost | In water or hydro |
|---|---|---|
| Watering | Soak when dry | Keep a little in the bottom |
| Growth rate | Faster | Slower, and it keeps its shape |
| Fungus gnats | Possible | Almost never |
| Where it can live | Indoors or outside | Indoors. It dislikes cold |
Moving from compost to water means washing every trace of compost off the roots. Anything left rots in the water and the rot spreads into the roots.
Water level and upkeep in a water setup
Keep the water level low enough that some roots are above it in air. Roots entirely submerged with no air is the same suffocation problem as waterlogged compost.
A clear container lets you see the level, which is useful, but it grows algae. Either change to an opaque container or wash it out monthly.
Mistakes people make after repotting
The two common ones are watering it as though nothing had changed, and feeding it straight away. A newly repotted plant has less root and fresh compost, so it needs less water and no feed for about a month.
The third is doing everything at once. Repotting and cutting back on the same day is two shocks together, and the plant sits still for weeks. Do one, wait a fortnight, then do the other.