SPECIAL TOPICS: POINSETTIAS

Poinsettia Care

The length of time your poinsettia will give you pleasure in your home is dependent on (1) the maturity of the plant, (2) when you buy it, and (3) how you treat the plant. With care, poinsettias should retain their beauty for weeks and some varieties will stay attractive for months.


Unwrap your poinsettia carefully and place in a sunny window. Keep the plant from touching cold windows.
Keep poinsettias away from warm or cold drafts from radiators, air registers or open doors and windows.
Ideally poinsettias require daytime temperatures of 60 to 70°F and night time temperatures around 55°F. High temperatures will shorten the plant’s life. Move the plant to a cooler room at night, if possible.
Check the soil daily. Be sure to punch holes in foil so water can drain into a saucer. Water when soil is dry. Allow water to drain into the saucer and discard excess water.
Fertilize the poinsettia if you keep it past the holiday season. Apply a houseplant fertilizer once a month.
  • Frequently Asked Questions

Are poinsettias poisonous?

Poinsettias are not poisonous. For nearly eight decades, this rumor has continued to circulate because of one unfounded story in 1919: that an Army officer’s two year old child allegedly died after eating a poinsettia leaf. While never proved by medical or scientific fact and later determined to be hearsay, the story has taken on a life of it’s own. But, the defenders of the poinsettia have pulled out all the scientific stops to allay public fears.

The Society of American Florists (SAF) worked with the Academic Faculty of Entomology at Ohio State University (OSU) to exhaustively test all parts of the poinsettia (Euphorbia pulcherrima). OSU researchers established that rats exhibited no adverse effects – no mortality, no symptoms of toxicity, and no changes in dietary intake or general behavior patterns – when given even unusually large amounts of different poinsettia parts. The United States Consumer Product Safety Commission (CPSC) accepts animal tests as valid indicators whether any product or natural growth is harmful to human health.

The OSU research was conducted 23 years ago and other sources have continued to reinforce the poinsettia’s safety.

According to the American Medical Association’s Handbook of Poisonous and Injurious Plants, other than occasional cases of vomiting, ingestion of the poinsettia plant has been found to produce no effect.

After reviewing all available poinsettia related information, the CPSC denied a petition in 1975 to require warning labels for poinsettia plants. Despite its continued circulation, the myth of the poinsettia is gradually losing steam.

Source: Society of American Florists

How do you get a poinsettia to bloom?

To get a poinsettia to reflower you have to keep it in total darkness between 5 pm and 8 am. Start this around October 1st and continue until color shows on the bracts; usually around early to mid-December. Any little exposure to light can prevent flowering. Covering the plant with a light-proof bag and placing it in a closet might work. Night time temperatures above 70-75°F can decay or prevent flowering.

How can I make my poinsettia last during the holiday season?

Place the poinsettia in a sunny window. Do not let any part of plant touch cold window panes.

  • Indoor temperatures from 60 to 70°F is ideal for long plant life.
  • High temperatures will shorten the life of the colorful bracts.
  • Water only when the soil is dry.
  • Placing your poinsettia in a cool room 55 to 60°F at night will extend blooming time.
  • Do not fertilize when plant is in bloom.
  • Avoid temperature fluctuations and warm or cold drafts.

I want to keep my poinsettia plants. When can I take them outside?

Move your poinsettia plant outdoors when all danger of frost has passed. Place it in a sunny area but where it will get moderate shade in the afternoon.

Should I fertilize my poinsettia if I am keeping it past the holiday season?

Fertilize once a month with a water soluble houseplant fertilizer.

How often should I water the poinsettia?

Be sure to remove foil covering drain holes before watering. Water only when the soil is dry. Do not let the poinsettia wilt. Do not let it sit with water in the saucer. Empty the saucer.

POINSETTIA PLANTING SITE

Poinsettias can be used in landscapes as accent plants or informal flowering hedges, as container plants for patios and decks, and as cut flowers for interior decorations. They should be planted in areas where they receive full sun most of the day.

Poinsettias require a long, dark period before they will initiate flower buds. Normally, they set flower buds in early October when nights are becoming increasingly longer. If the dark period is interrupted with the light from any other light source, flowering will be markedly delayed or the plant may not flower at all. Just a short period of light during the dark period is enough to delay or prevent flowering. This should be kept in mind when poinsettias are used in the landscape, and they should be planted in areas that will remain completely dark during the night.

Poinsettias grow best in moist, well drained, fertile soils. However, they will grow satisfactorily in a wide range of soils, including sand, muck, marl and clay The soil must be well drained because poinsettias will not grow well in wet areas.

Plants can be planted outdoors as soon as danger of frost is past. A general rule is to dig a hole 1’ (30.4 cm) wider and 6” (15.2 cm) deeper than the root ball. Backfill the hole with enough soil so the plant sits in the hole at the same depth it was growing in the container. Firm the soil to prevent settling, gently place the plant straight in the hole and fill around the ball with soil. Water thoroughly to remove air pockets. Mulch around plant.

Neglecting to fertilize will result in yellow leaves and ultimate loss of lower leaves. Plants should be fertilized monthly, starting in March with 2 lbs. (1 kg) of 18-6-12, per 100 square feet (10 m2) of planting area. Continue monthly applications of the fertilizer until October.

Water relations are a crucial for growing poinsettias, prolonged dryness will result in the loss of lower leaves. The soil should be kept moderately moist at all times. Poinsettias should be pruned in early spring after blooming is over and the danger of frost has passed. They should be cut back to within 12 to 18” (30.5 to 45.7 cm) of the ground unless they have been frozen below this point, in which event they should be cut back to "live" wood.

Pinching the plant during growing season will result in a compact plant at flowering time. After four weeks, new growth should be cut back, leaving four leaves on each shoot. Repeat every time new growth develops until about September 10th . New growth after last pinch will grow 8 to 10” (20.3 to 25.4 cm) and, in the first week of October, will initiate flower buds.

Pruning after September 10th does not allow enough time for side shoots to grow and develop before bud initiation in early October. As a result, the bracts will be much smaller than those on a plant where the last pinch was made before September 10th.

For more information and charts go to: http://edis.ifas.ufl.edu/MG352
Poinsettias For Florida, Indoors and Outdoors. Robert J. Black, Rick K.Schoellhorn. Environmental Horticulture Department, Florida Cooperative Extension Service, Institute of Food and Agricultural Sciences, University of Florida. Original publication date January 22, 2002.

POINSETTIA PROBLEMS

Flowering Disorders: Flowering will be markedly delayed or plants may not bloom at all if dark period (night) is interrupted by light during early October. Periods of dark, rainy weather in late September and early October often shorten days causing plant to set buds and flower early. In addition, temperatures above 70°F (21°C) during the bud-forming periods will delay flowering. Flower development is best when night temperatures range from 60 to 62°F (15.6 to 16.7°C).

Flowers that develop on unbranched stems more than 14” (35.6 cm) in length or that have 20 to 30 leaves usually develop physiological disorders called "splits." Stems that do not normally branch unless pinched will suddenly branch at growing tip, each branch will flower, producing a cluster of small bracts with an open center. Splits can be avoided by routine pinching.

Magnesium Deficiency: Ornamental plants show a difference in susceptibility to magnesium deficiency because some plants develop symptoms while others may not. Magnesium deficiency occurs to a considerable extent in poinsettias grown in the landscape. The symptoms of magnesium deficiency yellowing and marginal scorch or tip burn beginning on leaves at the base of the shoots and advancing toward the tip. Apply magnesium sulfate (epsom salt) twice yearly (February or March and June or July) at 1 teaspoon per square foot, 3 tablespoons per square yard (45.2 cm3/0.8 m2), or 2 cup (1 pound) per 100 square feet (454 g/10 m2).

Freeze Damage: The poinsettia is very sensitive to cold, and many years plants are frozen before they have had a chance to bloom or soon after they have bloomed. Freeze damage is particularly a problem in unprotected locations of north Florida. Often, plants are killed to the soil line: however, they usually send up new shoots from the crown come springtime.

Pests: Poinsettias have pest problems, and to grow specimen plants, these problems must be recognized and control measures initiated. Insects and mites damage poinsettias by sucking plant juices. Occasionally worms (larvae) will feed on poinsettias. The poinsettia hornworm is a particularly serious problem, since it can rapidly defoliate an entire plant. When pest infestations are severe chemical control may be needed. For recommendations on selection and application of insecticides and miticides, contact the Cooperative Extension Service Office in your county.

Diseases: Poinsettia scab (Sphaceloma poinsettiae) is a fungal disease that may attack poinsettias, causing circular spots of a light cream color of the midrib and veins of leaves and raised, often elongated lesions or cankers on stems and leaf petioles. Scab is most prevalent in the summer, and scab-infected branches should be pruned and discarded. Plants may be attacked by fungi, causing both root and stem rots. Selection of well drained planting sites and good watering practices can help prevent the occurrence of these diseases. When symptoms are apparent, it is usually too late to control root and stem rot disease. The diseased plant should be removed and the area treated with a soil fumigant or fungicidal drench before placing another poinsettia. For recommendation on selection and application of fungicides and soil fumigants, contact the Cooperative Extension Service Office in your county.

For more information and charts go to: http://edis.ifas.ufl.edu/MG352
Poinsettias For Florida, Indoors and Outdoors. Robert J. Black, Rick K.Schoellhorn. Environmental Horticulture Department, Florida Cooperative Extension Service, Institute of Food and Agricultural Sciences, University of Florida. Original publication date January 22, 2002.

 

POINSETTIA SELECTION & CARE

Poinsettias are traditionally grown as Christmas pot plants, and breeders have been concerned with improving them for this purpose. They worked to produce a fast-growing, compact pot plant which would retain its leaves and bracts under the less-than-favorable conditions found in the home.

Each holiday season, the number one flowering plant sold in America is the Poinsettia. There is always some confusion about the best way to care for and display this popular plant. The following are some tips for getting the most from a Poinsettia during the holidays.

Poinsettias are tropical plants and prefer a temperature range of 65°F night and 75-80°F daytime temperatures. When purchasing poinsettias for the home, avoid plants that have been allowed to sit outside in the cold, or in windy areas, as these plants will have reduced quality when you bring them indoors. The beautiful bracts of poinsettias are easily damaged by crowding and rough handling, so check to make sure that leaves and bracts are not damaged before purchasing your plant.

Location - Keep plants in a warm location free of drafts and chilling. Bright light is always best, but avoid placing plants in extremely sunny, hot, and dry situations.

Watering - Water your poinsettia when the surface of the soil is dry to the touch. Remove any excess water from the saucer beneath the plant as Poinsettias do not like to have soggy soil. Most people kill their poinsettias with too much water. Remember this plant came from the tropical desert and in more tolerant of dry conditions than of wet.

Humidity - Poinsettias like a little bit higher humidity than the average household but will do fine in most situations without additional humidity. Misting plants or placing them on gravel trays will prolong the color and life of the poinsettia.

Fertilization - It is not necessary to fertilize your poinsettia during the holiday season. In fact, high levels of fertilizer will reduce the quality of the plant. If you want to keep your poinsettia past the holiday season, see the section on caring for your plants after the holidays.

For more information and charts go to: http://edis.ifas.ufl.edu/MG352
Poinsettias For Florida, Indoors and Outdoors. Robert J. Black, Rick K.Schoellhorn. Environmental Horticulture Department, Florida Cooperative Extension Service, Institute of Food and Agricultural Sciences, University of Florida. Original publication date January 22, 2002.

RE-BLOOM POINSETTIAS

Re-blooming is a tricky proposition in most parts of Florida. Plants require 14 hours of complete darkness each day for 6-8 weeks before flowering. This is usually difficult to provide in the home or landscape due to outdoor street or security lights, which will prevent flowering.

If you are determined to try re-blooming, however, here is a brief timeline to help you in getting a second year of flowering from your poinsettia:

• In July cut the plant back to about ? the height you desire for your holiday season.
• On October 1st, begin 14 hours of uninterrupted darkness each night, every night without interruption.
• Continue this until the holidays arrive.
• Each night you do not provide uninterrupted darkness roughly equals a one day delay in getting holiday color.

 
For more information and charts go to: http://edis.ifas.ufl.edu/MG352
Poinsettias For Florida, Indoors and Outdoors. Robert J. Black, Rick K.Schoellhorn. Environmental Horticulture Department, Florida Cooperative Extension Service, Institute of Food and Agricultural Sciences, University of Florida. Original publication date January 22, 2002.