that no one wanted after the holidays and they started to drop leaves and get ugly. They would languish all winter, some dropping all their leaves. But in the spring, they would put out new growth. I did keep them in the house for a couple of years, and they did survive well and looked good. But they never bloomed again. So now, I just wait till spring and I plant them out in the garden. They have beautiful full leaves and are a nice compliment plant. If I were so inclined, I could have dug them up and brought them back in the house for the winter, but I didn't bother. I just know that they do very well outside through the summer, although they do not turn red.

I have never seen seeds, but I have never looked. I have a feeling that the ones you buy for the holidays would not reproduce well. I did buy some seeds once, but they never germinated. Cuttings would be an easier and more successful method of reproducing them, at least from what I have seen.

Editted to add: I just hate to see a plant die----and that is the reason I would round them all up. For some reason, end of season frost kills don't bother me as much.

http://en.wikipedia.org/wiki/Poinsettias

Cultivation

With care, the poinsettia can be induced to reflower after the initial display when purchased. The red blooms should be pruned, and the plant moved outdoors after the last frost. It should be returned indoors in the Fall, before the first frost, to a room which is not lighted after sunset. The plant requires a period of uninterrupted long, dark nights for around two months in autumn in order to develop flowers. Incidental light at night during this time will hamper flower production. When watering it is important to allow the plant to drain out any excess water. Having a poinsettia sit in water can do harm to the plant as it prefers moist soil to direct water.

In order to produce extra axillary buds that are necessary for plants containing multiple flowers, a phytoplasma infection – whose symptoms include the proliferation of axillary buds – is used.[

I'm pretty sure they're all grown from cuttings. Also, as someone mentioned above, it is a PITA to get them to re-flower. Requires periods of total darkness, etc.

Repot in spring. Leave otside all summer. I put mine down in the basement under a grow light in the fall. 10 hours of light, mine is blooming like crazy right now. Blooms aren't as big but it's pretty.

I have one that's 3 years and I drag it in each winter and then out again in late spring.

in the open. Sad. I love the big ones.