Buying, Caring for and Reblooming your Poinsettia By Paula Szilard General: In the United States growing poinsettias has become a very big business. There are over 75 million sold in the United States annually, more than any other plant, including orchids and mums. Growing them is a very precise and lengthy effort often starting in March and carefully choreographed to get plants into retail outlets as early as November 1st and throughout the holiday season. Poinsettias are tropical and subtropical shrubs originating in Mexico. They can be grown outdoors in USDA hardiness zones 9-11. Thus, you sometimes see poinsettia hedges in Hawaii and other tropical climates. They don’t look like much until they begin flowering in the shorter days of fall, but when they do, they are glorious! Occasionally they are allowed to get very large and are pruned into small trees. The poinsettia is named after Joel R. Poinsett, our first ambassador to Mexico, who is credited with introducing this plant to America in 1828. He was quite taken by the blooming plants he saw in Mexico and had cuttings shipped back to his home in South Carolina. Botanists refer to the poinsettia as Euphorbia pulcherrima (the most beautiful euphorbia) and place it into the Euphorbiaceae family along with such plants as crown of thorns, crotons (codiaeums), chenille plants (acalyphas), tapioca (Manihot esculenta) and Hevea brasiliensis, the plant that provides us with latex and of course, rubber. The poinsettia is known for its vividly colored bracts, which appear in late fall. What most people call flowers are really bracts or colored leaves. The real flowers are the small yellow blossoms at the top of the bracts. Poinsettias have the reputation of being poisonous because their sap is somewhat irritating. You may want to stay away from it if you have latex allergies. However, it takes large quantities of ingested plant material to sicken children and pets. According to the POISINDEX Information Service, a 50-lb. toddler could eat about 500 colored bracts and not be harmed. Still, it’s unwise to keep these plants where toddlers can reach them. It can’t be good for them. To bloom, poinsettias need short days and long nights of uninterrupted darkness. This means from late September until they come into bloom they need 12-14 hours of darkness each day. When you buy them, of course, all the hard work of bringing them into flowering has already been done. You just need to take care of them so they last through the season and maybe beyond. Buying When you buy poinsettias, keep an eye on the following: Choose plants that are upright. Branch angles should be about 60 degrees. Branches joined at right angles tend to be brittle. The plant should be 2½ times as tall as the diameter of the container. Choose plants with bracts that are completely colored. Avoid plants with immature bracts. These were shipped to early and will not mature. Apart from the colored bracts, leaves should be dark green down to the soil level. The plant should look full and balanced and be attractive from all sides. Do not buy drooping or wilting plants. Do not buy plants that are still in their paper or plastic sleeves. Accumulating ethylene gas produced by the plant causes leaf drop and drooping. The longer the sleeves stay on, the longer it takes for the plants to recover. Check the soil moisture. If the soil is wet, but the plant is nonetheless wilted, you could have a root rot problem on your hands. Buy plants with newly maturing cyathia (yellow flowers). The pollen should just be starting to show. If the cyathia are loose or extended, don’t buy the plant. It’s over the hill. Care and Reblooming A lot of people think it’s too much trouble to try reblooming their plants. However, if you are serious, here is what you need to do to take care of your poinsettia and get it to rebloom: Keep your plant away from drafts, out of the cold and away from heat vents, fireplaces, radiators and other sources of heat. Temperatures between 60 F and 80 F are best. Keep the soil uniformly moist. If you keep it too dry, there is excessive leaf drop. You should not fertilize your plant until you have had it at least thirty days. It got plenty of fertilizer during the production phase of its life. Keep your plant in bright, indirect light. In late March or early April, cut your poinsettia back to about 8” in height. Continue regular watering and fertilize with a balanced all purpose formula every 2 weeks. By the end of May, you should see significant growth. Give your plant a long summer vacation by placing it outdoors in the sun or partial sun until the nights get cold. Acclimatize it to the sun by increasing the exposure gradually. Some people sink the pot into the ground. In June, you can transplant your plant into a larger pot that is no more than 4 inches larger than the original pot. You will notice that as the growth regulators used in production wear off, your plant will grow a lot taller. You will probably need to prune it back again in late June or early July. While it is outside, fertilize every two weeks. Use an all purpose formula or one that has more nitrogen and potassium than phosphorus. Whatever formula you use, it should also contain all of the micronutrients. Poinsettias are photoperiodic, which means flowering is controlled by the length of day or length of night. They are classified as short day bloomers. This means that to bloom, these plants must have short days and long nights beginning in late September, usually around September 19th. Of course, you may need to bring your plant in before then if the weather gets cold. Beginning on this date give your plant bright, indirect light during the day and long nights of 12-14 hours. Please note that this period of darkness cannot be interrupted by even the smallest amount of light. Depending on the specific cultivar, this process can take anywhere from 8 to 9 weeks. To achieve this uninterrupted period of darkness, you could cover the plant with an overturned wastebasket or a thick, black plastic bag, or you could place it in a dark closet. Just make sure that you uncover it again or remove it from the closet during the daylight hours. Also continue your regular watering and fertilizing. And don’t forget, you must be totally consistent about not exposing it to any nighttime light. The bracts should color up and the plant should bloom for the holidays. Poinsettia care is fairly straightforward, but reblooming one is really quite difficult. Consistently providing a long period of long uninterrupted nights is not at all easy. This is usually where the rubber meets the road. Sometime ago a friend wanted to know how to bring her poinsettia back into bloom for the next season and when I told her what do, she said, “But that’s like having a kid!” Yes, maybe it is—a little! And now we know why over 75 million plants are sold year after year after year and why the industry grosses over 220 million annually! Sources: Ball Redbook, 16th ed. Vic Ball, editor. Batavia, IL: Ball Publishing, 1997. Nell, Terril A. Flowering Potted Plants: Prolonging Shelf Performance—Postproduction Care and Handling. Batavia, IL: Ball Publishing, 1993. O’Meara, Carol. Holiday Plant Selection and Care. Colorado State University Extension. Available on the CSU Extension Website: www.ext.colostate.edu. (11/12/09) Paul Ecke Poinsettias. Website: www.pauleckepoinsettias.com. (11/12/09) Poinsettia Pages. University of Illinois Extension. Website: http: //urbanext.illinois.edu/poinsettia/index. (11/12/09) Smithsonian Institution. Horticulture Services Division. Poinsettia Fact Sheet: www.gardens.si.edu.horticulture/res

Buying, Caring for and Reblooming your Poinsettia

Paula Szilard

General:

In the United States growing poinsettias has become a very big business. There are over 75 million sold in the United States annually, more than any other plant, including orchids and mums. Growing them is a very precise and lengthy effort often starting in March and carefully choreographed to get plants into retail outlets as early as November 1st and throughout the holiday season.

Poinsettias are tropical and subtropical shrubs originating in Mexico. They can be grown outdoors in USDA hardiness zones 9-11. Thus, you sometimes see poinsettia hedges in Hawaii and other tropical climates. They don’t look like much until they begin flowering in the shorter days of fall, but when they do, they are glorious! Occasionally they are allowed to get very large and are pruned into small trees. The poinsettia is named after Joel R. Poinsett, our first ambassador to Mexico, who is credited with introducing this plant to America in 1828. He was quite taken by the blooming plants he saw in Mexico and had cuttings shipped back to his home in South Carolina. Botanists refer to the poinsettia as Euphorbia pulcherrima (the most beautiful euphorbia) and place it into the Euphorbiaceae family along with such plants as crown of thorns, crotons (codiaeums), chenille plants (acalyphas), tapioca (Manihot esculenta) and Hevea brasiliensis, the plant that provides us with latex and of course, rubber.

The poinsettia is known for its vividly colored bracts, which appear in late fall. What most people call flowers are really bracts or colored leaves. The real flowers are the small yellow blossoms at the top of the bracts. Poinsettias have the reputation of being poisonous because their sap is somewhat irritating. You may want to stay away from it if you have latex allergies. However, it takes large quantities of ingested plant material to sicken children and pets. According to the POISINDEX Information Service, a 50-lb. toddler could eat about 500 colored bracts and not be harmed. Still, it’s unwise to keep these plants where toddlers can reach them. It can’t be good for them.

To bloom, poinsettias need short days and long nights of uninterrupted darkness. This means from late September until they come into bloom they need 12-14 hours of darkness each day. When you buy them, of course, all the hard work of bringing them into flowering has already been done. You just need to take care of them so they last through the season and maybe beyond.

Buying

When you buy poinsettias, keep an eye on the following:

Choose plants that are upright.

Branch angles should be about 60 degrees. Branches joined at right angles tend to be brittle.

The plant should be 2½ times as tall as the diameter of the container.

Choose plants with bracts that are completely colored. Avoid plants with immature bracts. These were shipped to early and will not mature.

Apart from the colored bracts, leaves should be dark green down to the soil level.

The plant should look full and balanced and be attractive from all sides.

Do not buy drooping or wilting plants.

Do not buy plants that are still in their paper or plastic sleeves. Accumulating ethylene gas produced by the plant causes leaf drop and drooping. The longer the sleeves stay on, the longer it takes for the plants to recover.

Check the soil moisture. If the soil is wet, but the plant is nonetheless wilted, you could have a root rot problem on your hands.

Buy plants with newly maturing cyathia (yellow flowers). The pollen should just be starting to show. If the cyathia are loose or extended, don’t buy the plant. It’s over the hill.

Care and Reblooming

A lot of people think it’s too much trouble to try reblooming their plants. However, if you are serious, here is what you need to do to take care of your poinsettia and get it to rebloom:

Keep your plant away from drafts, out of the cold and away from heat vents, fireplaces, radiators and other sources of heat. Temperatures between 60 F and 80 F are best.

Keep the soil uniformly moist. If you keep it too dry, there is excessive leaf drop.

You should not fertilize your plant until you have had it at least thirty days. It got plenty of fertilizer during the production phase of its life.

Keep your plant in bright, indirect light.

In late March or early April, cut your poinsettia back to about 8” in height. Continue regular watering and fertilize with a balanced all purpose formula every 2 weeks. By the end of May, you should see significant growth.

Give your plant a long summer vacation by placing it outdoors in the sun or partial sun until the nights get cold. Acclimatize it to the sun by increasing the exposure gradually. Some people sink the pot into the ground.

In June, you can transplant your plant into a larger pot that is no more than 4 inches larger than the original pot.

You will notice that as the growth regulators used in production wear off, your plant will grow a lot taller. You will probably need to prune it back again in late June or early July.

While it is outside, fertilize every two weeks. Use an all purpose formula or one that has more nitrogen and potassium than phosphorus. Whatever formula you use, it should also contain all of the micronutrients.

Poinsettias are photoperiodic, which means flowering is controlled by the length of day or length of night. They are classified as short day bloomers. This means that to bloom, these plants must have short days and long nights beginning in late September, usually around September 19th. Of course, you may need to bring your plant in before then if the weather gets cold. Beginning on this date give your plant bright, indirect light during the day and long nights of 12-14 hours. Please note that this period of darkness cannot be interrupted by even the smallest amount of light. Depending on the specific cultivar, this process can take anywhere from 8 to 9 weeks. To achieve this uninterrupted period of darkness, you could cover the plant with an overturned wastebasket or a thick, black plastic bag, or you could place it in a dark closet. Just make sure that you uncover it again or remove it from the closet during the daylight hours. Also continue your regular watering and fertilizing. And don’t forget, you must be totally consistent about not exposing it to any nighttime light.

The bracts should color up and the plant should bloom for the holidays. Poinsettia care is fairly straightforward, but reblooming one is really quite difficult. Consistently providing a long period of long uninterrupted nights is not at all easy. This is usually where the rubber meets the road. Sometime ago a friend wanted to know how to bring her poinsettia back into bloom for the next season and when I told her what do, she said, “But that’s like having a kid!” Yes, maybe it is—a little! And now we know why over 75 million plants are sold year after year after year and why the industry grosses over 220 million annually!

Sources:

Ball Redbook, 16th ed. Vic Ball, editor. Batavia, IL: Ball Publishing, 1997.

Nell, Terril A. Flowering Potted Plants: Prolonging Shelf Performance—Postproduction Care and Handling. Batavia, IL: Ball Publishing, 1993.

O’Meara, Carol. Holiday Plant Selection and Care. Colorado State University Extension. Available on the CSU Extension Website: www.ext.colostate.edu. (11/12/09)

Paul Ecke Poinsettias. Website: www.pauleckepoinsettias.com. (11/12/09)

Poinsettia Pages. University of Illinois Extension. Website: http: //urbanext.illinois.edu/poinsettia/index. (11/12/09)

Smithsonian Institution. Horticulture Services Division. Poinsettia Fact Sheet: www.gardens.si.edu.horticulture/res_ed/fctsht/poinst.htm. (11/12/09)