Poinsettias are synonymous with Christmas. Native to the U.S. Southwest and Mexico, they are prized for their large scarlet blooms in the winter. In their native area they can grow to 10 feet tall. Poinsettias are most often purchased from nurseries, but seeds can be ordered from many of the major seed catalogues. Poinsettias are short day bloomers, meaning they require darkness in order to set flowers. You can force the blooms to have them in full colour by the holidays.
Sow one seed per pot right beneath the soil surface. Poinsettias do not need light to germinate. Keep the soil moist and warm until the seeds germinate in 1 to 2 weeks.
Set poinsettias near a fan to cut down on fungal attacks until the first few leaves grow in. The moving air will strengthen the plant and prevent fungus spores from settling.
Fertilise the poinsettia once a month during the warm months. Water when the soil becomes dry to the touch.
Force poinsettias to bloom before Christmas by placing in a dark room for 14 hours every night. Another option is to cover the plant in a black trash bag.
Move poinsettias outside in the warm months and bring them back inside before the first frost.
Poinsettias can be trimmed with pruning scissors. Harvest seeds from existing plants by removing the seed pod after the bloom fades. Dry seeds thoroughly before planting.
Poinsettias are not poisonous but they may cause stomach aches if ingested by pets or people.