Poinsettia care isn't very difficult, but there are few things to know about poinsettias that affect how they should be looked after in your home. This Christmas favourite actually originates from the dry forests of Central America, which have a very different climate to the winters in the Northern Hemisphere.
This, in a nutshell, is why many poinsettias don't make it through the Christmas festivities, let alone through the winter. However, there are a few things you can do to make a poinsettia more comfortable, and, with a bit of luck, even enjoy a second flowering next year.
1. Buy your poinsettia from a reputable garden centre
The reason why many poinsettias die almost as soon as they are gifted for Christmas is because they were kept in inappropriate conditions where they were sold. Supermarkets often display poinsettias right next to the entrance, which means these delicate tropical plants get blasted with cold draughts all day; by the time they've been bought, they've already begun dying.
This is why buying yours from a plant nursery or garden centre will pay off: it will have been kept properly by plant specialists.
2. Give poinsettias the correct amount of light
Poinsettias like a lot of light – but only during the day. These plants are used to bright, sunny days and pitch-black nights, so, for best results, place it on a bright windowsill during the day, and then put it away into a dark cupboard for the night (at least 12 hours is recommended). Too much electric lighting and insufficient darkness at night is confusing for this plant.
3. Keep poinsettias at a constant temperature
This is true of most tropical plants, and poinsettias are no exception: they like a constant, warm-but-not hot temperature, with no sudden fluctuations. That rules out placing them next to windows that are often opened, as well as next to sources of heat. Even having the leaves of the plant touch an overly cold window pane can make them ill. The ideal temperature for them is around 18 to 20ºC, so a bright spot in a living room or bedroom is best.
4. Don't overwater
It's important to let your poinsettia dry out completely between waterings; at the same time, if the root of the plant dries out, it will die. What this means in practice is watering a little every couple of days. Make sure the plant does not stand in water. You can also try the root-watering method: drench the root of the plant in water, then replace in its pot when the water's drained completely.
5. How to keep poinsettias alive year-round
It's perfectly fine to compost your poinsettia after the festive season, but it is a perennial, and, with proper care, will flower again next year. The main things to know about poinsettia care throughout the year is that they like being outside during the summer, and that you will need to keep it in complete darkness (while still occasionally watering) between mid-October and mid-November. Other than that, just follow the tips above, and you should have a healthy plant that will delight again and again.