Saving can be a challenge. You just have to understand how a poinsettia works. Once the Christmas presents have all been opened and holiday decorations are packed away, treat your poinsettia like any other houseplant. Do not over water or under water a poinsettia plant.
During the spring and summer, a poinsettia is a green foliage plant. When the weather turns warm, re-pot your poinsettia. You also need to decide whether you want your plant to be a bush or a tree.
Where you keep your poinsettia between New Year's and September doesn't make a whole lot of difference, as long as it gets light, the tricky part comes after September.
To flower, the plant needs the same amount of darkness Mother Nature provides, somehow, you've got to keep that plant in the dark after the sun goes down, and it has to stay in the dark until the sun comes up. If there is any flash of light, you can forget it.
Once the plant begins turning the bright red it's known for, there's no turning back, because once it starts turning, it's going to go, it's already set physiologically.
Other Christmas Plants: Cyclamen & Christmas Cactus