Euphorbia pulcherrimaPoinsettia
科:大戟科
Family:Euphorbiaceae
属:大戟属
common name:Poinsettia
introduce:Plant Type: Deciduous shrub
Family: Euphorbiaceae
Missouri Native: No
Native Range: Mexico
Height: 3 to 10 feet
Spread: 3 to 7 feet
Bloom Time: Seasonal bloomer
Bloom Color: Yellow flowers with red bracts
Sun: Part shade (only)
Water: Medium moisture
Maintenance: High
General Culture:
In Mexico, poinsettia is a perennial flowering shrub that will grow to 10 ?15 feet. Many poinsettia plants are sold with a decorative brightly-colored aluminum or plastic pot wrapper. They are pretty, but both aluminum and plastic wrapping block water drainage. You need to remove the covering or punch holes for drainage. Poinsettia plants are extremely brittle. Handle with care so as not to snap branches. Place your plant in a bright area away from all cold air (like doors) and all cold drafts. Otherwise, cool indoor household temperatures are just fine. Poinsettia plants like to be kept on the dry side. Water as often as needed, but allow soil surface to dry before watering again, then soak the soil. Be certain all excess water is drained away and discarded. Fertilizer is not necessary, if your poinsettia is a Christmas holiday plant. If kept throughout the winter, after blooming reduce the amount of water and allow the plant to go dormant. Move the plant to a cooler position but not below 50癋. You can begin fertilizing in the spring, and every two weeks until early December with a 1 teaspoon per gallon solution. If you wish to grow your poinsettia for the next Christmas, cut back your plant in spring (April is a good month) and start fertilizing. Outside of zones 9 ?11, place your plant outdoors in an eastern sun or general shade after you have reliable temperatures above about 60癋. You can also repot at this time. Keep the plant pinched all summer to produce the main branches you want with plenty of good growing tips (these tips are what will produce color). As fall approaches, bring your plant indoors to a bright location when temperatures threaten to go below 60癋.To initiate color change, starting the end of September or the beginning of October, place your poinsettia in complete darkness a minimum of 12 hours per day. (Shield the plant from any light from 5:00 PM until morning light.) During the day, provide as much bright light as possible. Continue watering and fertilizing during this period. When strong color appears in the bracts, it is no longer necessary to put the plant in darkness at night. If all of the requirements have been met, you should see color by the middle of November.
Noteworthy Characteristics:
In Mexico poinsettia is a straggly deciduous shrub, the most widely grown of all shrubby Euphorbias. Inconspicuous yellow flowers are surrounded by large brilliant red floral bracts (modified leaves) in winter through spring. Contrary to conventional wisdom, poinsettia plants are not a poisonous plant. A Ohio State University study showed that a 50 pound child could eat 500 bracts and might have a slight stomach ache. However, the white sap can have allergic properties, especially for people who have latex allergies.
Problems:
Problems may include whitefly, mealybugs, red spider mites and scale. Root or stem rots can also occur if overwatered.
Uses:
Grown primarily as a pot plant, poinsettias are a big industry representing about 85% of potted plant Christmas season sales. The USA exports about 90% of the world抯 poinsettia plants. It is thought that poinsettias are grown commercially in greenhouses in all 50 states and over 60 million plants are produced for sale.
