Water poinsettias when the top of the soil feels dry, rather than on a strict calendar schedule. For most indoor plants in typical winter home conditions, this ends up being about once a week, sometimes up to every 7–10 days.
How often to water
- Check the soil with your finger every day or two; water when the top 1–2 inches feel dry, and skip watering if it still feels moist.
- In a warm, bright room or very light potting mix, you may need to water more often (every few days); in cooler rooms, less often (closer to once a week or a bit longer).
How much water to use
- Water thoroughly until you see water come out of the drainage holes, then pour off any water that collects in the saucer so the roots do not sit in it.
- As a rough guide, a standard small poinsettia in a 13 cm (about 5 inch) pot often needs around 100 ml per watering, while mini plants in tiny pots need only a small shot-glass amount.
Signs of over- or underwatering
- Overwatering: consistently wet soil, yellowing leaves, and leaf drop, sometimes with limp stems, usually mean you are watering too often or leaving the pot standing in water.
- Underwatering: very light pot, dry soil, wilting, and dropping leaves that feel dry or crispy indicate you waited too long between waterings.
Seasonal adjustment
- During the main holiday display period, keep watering when the soil surface dries; after flowering, the plant rests and usually needs less water, often about once a week in a cooler spot without letting the soil bone-dry.
- Mini poinsettias dry out faster than large ones, so expect to check and possibly water them a bit more frequently, using only a small amount each time.
