Poinsettias Euphorbia pulcherrima are perennial Mexican plants that produce a ring of red, pink or white leaves during the winter. This makes them a favorite Christmas houseplant. Most people discard their poinsettias after the holidays as soon as they start to lose their colorful leaves. With the correct pruning and care throughout the year, they produce a fresh display of colorful leaves for Christmas every year.
Place your poinsettia on a windowsill that receives direct sunshine, but do not let the leaves touch the glass. Poinsettias thrive at day temperatures of between 60 and 70 degrees Fahrenheit. Their red leaves last longer if kept at between 55 and 60 degrees at night. Water when the surface of the soil is dry, providing enough water to evenly soak the soil. Allow all excess water to drain away.
Winter and Spring Care
Cut back the main stems on your plant once its flowers have dropped off and its red leaves have faded. Leave around 6 inches of stem holding up to three leaves. Place your poinsettia on a sunny windowsill and water when the surface of the soil dries out. Fertilize every two weeks with a liquid houseplant fertilizer.
Place your poinsettia outdoors once minimum temperatures rise above 60 degrees Fahrenheit. Choose a location exposed to morning sunshine. Pinch out the plant's growing tips once its stems are at least 5 inches long. For larger plants, repinch in late summer.
Move your poinsettia plant indoors to a sunny windowsill during the early autumn before temperatures drop below 50 degrees Fahrenheit. To produce flowers, poinsettias must experience complete darkness for at least 12 hours every day for eight to 10 weeks. Place in a completely dark room or a light-proof box or closet between 5 p.m. and 8 a.m. every day from October on. Keep temperatures below 70 degrees Fahrenheit.
Keep store-bought poinsettia plants warm on the journey home as their leaves wilt at temperatures below 50 degrees Fahrenheit. Never leave poinsettias standing in a dish or water. Repot poinsettias at the same time as their spring prune. Use free-draining compost containing sand or vermiculite to aid drainage.