Talking Plants

University of Minnesota, Clay County

The holiday season is here once again, and it is time to select your poinsettia. Stores have been filling up with numerous varieties of poinsettias ranging in color from red, white, salmon, plum, red with white splashes, burgundy, to name a few. There are also different sizes of poinsettias available ranging in height from three to five inches up to four or five feet. With so many choices it can be a real challenge to select just one.
Choosing the perfect poinsettia is based on one’s personal preference. The smaller sizes are great for a centerpiece on the dinner table because everyone can see over them. The larger sizes are great for a coffee table or on the floor where height is not a factor. When selecting your poinsettia check a few colored bracts (modified leaves) as well as some of the green leaves to make sure they are free of leaf spots and insects. Before leaving the store, make sure your poinsettia is properly covered using a plastic bag filled with warm air. Chilling injury can occur if poinsettias are directly exposed to temperatures below 50 degrees F.
Poinsettias will remain healthy and colorful longer if placed in a sunny location away from heat vents and cold drafts. The ambient temperature should be around 65 to 70 degrees F. The soil should be kept moist but not saturated. Water poinsettias thoroughly when the soil surface is dry and make sure all excess water is removed from the saucer. When new growth develops (usually in late spring), water poinsettias with an all-purpose houseplant fertilizer mixed half strength every three to four weeks.
With a little work, poinsettias may be forced to re-bloom the following Christmas. In late April or early May prune the plant back to about eight inches to encourage branching and continue to keep in a sunny location. Once the danger of frost has passed and night temperatures have warmed, place the poinsettia outdoors in a location that is protected from the midday sun. If needed, transplant your poinsettia into a pot that is two to three inches bigger in diameter than the original pot. Add fresh potting soil that is similar to the original soil.
Bring the poinsettia indoors when night temperatures begin to cool and place in a sunny location. Starting the middle of September or early October the plant needs to be kept in total darkness for 14 hours each night. This can be done by placing the poinsettia in a closet, cupboard, basement, or by placing a black trash bag over the plant; any method that will exclude all light is acceptable. Each day, return the poinsettia to its sunny location. This routine needs to be done daily without fail until the bracts have turned color, usually eight to ten weeks. Any disruption to this routine could cause bract coloration to be delayed or completely absent.
A common question that arises this time of year concerns the alleged poisonous nature of the poinsettia plant. Research conducted by The Ohio State University looked at the toxicity of leaves and sap and concluded the plant is non-toxic. Of course, the poinsettia, like many other houseplants, is not intended for human or animal consumption. Place your poinsettia in a location out of reach by young children and curious pets.
University of Minnesota,Clay County 218.299.5020.
Check out our website at https://local.extension. umn.edu/local/clay