Poinsettias remain one of the most popular holiday plants, synonymous with Christmas décor and festive cheer. The familiar red plant, native to Mexico, has been joined by even flashier hues thanks to hybridizers who have expanded the range of colors from the familiar scarlet to white, cream, salmon, yellow, and pink.
The poinsettia plant is actually a shrub, Its blooms are a cluster of tiny yellow flowers surrounded by large brilliant (usually red) floral bracts, which are modified leaves. Also known as Mexican flameleaf, these plants are forced into bloom in time for the holiday season, and they require specific care to look their best into the new year and beyond.
Contrary to a popular myth, poinsettias and not toxic to people or pets. At most, they are mildly toxic to cats and dogs who ingest the plant material.
|Common Name||Poinsettia, Mexican flameleaf, Christmas star|
|Botanical Name||Euphorbia pulcherrima|
|Plant Type||Perennial, shrub|
|Mature Size||3–10 ft. tall, 3–7 ft. wide|
|Sun Exposure||Full, partial|
|Soil Type||Loamy, well-drained|
|Soil pH||Neutral to acidic|
|Flower Color||Yellow; bracts (modified leaves) are usually red but other colors are available|
|Hardiness Zones||9–11 (USDA)|
|Toxicity||Mild symptoms to dogs and cats but not poisonous. The white sap can have allergic properties for people with latex allergies.|
There is no need to discard your poinsettia come January—you can keep it healthy and vigorous throughout year with the right care. The trick: Provide enough filtered sun, warmth, and water, and your poinsettia thrive. If you're especially motivated and follow a regimen of specific care, your plant might rebloom next holiday season.
Poinsettia do best when placed in bright, diffused sunlight, so place your plant near a sunny window where it will receive at least six to eight hours of diffused light per day. Although the plants can survive with fewer hours of light, they won't be as vigorous or as long-lived . Be aware that exposure to direct sunlight can burn bracts and leaves.
While poinsettias are typically purchased already potted from a garden center or nursery, if you're planting (or replanting) a poinsettia, choose a well-draining peat-based potting soil for best success.
Water your poinsettia whenever the soil surface feels dry to the touch. Saturate the soil completely until water runs through the drainage holes in the bottom of the pot, but do not let the plant sit in water. If the pot was wrapped in decorative foil, be sure to poke a few holes through the bottom to allow excess water to drain away Overwatering is the quickest way to kill a poinsettia, and wilting leaves are usually a sign of overwatering.
Temperature and Humidity
To keep your poinsettia in bloom as long as possible, maintain a temperature of 65 to 75 degrees Fahrenheit during the day. A slight drop in temperature at night will not hurt the plant. However, cold drafts, allowing the leaves to touch a cold window, or more importantly, a lack of adequate light, can injure the leaves and cause premature yellowing and leaf drop.
Lack of humidity during dry seasons, particularly during winter, is an ongoing problem for most houseplants, including poinsettias. If your home tends to be dry, consider investing in a small space humidifier to increase humidity levels in the area surrounding your poinsettia.
Do not fertilize Mexican flameleafs during their blooming period. When keeping the plant throughout the year, you can begin fertilizing in the spring at half-strength when there's no growth, but not until then. Feed every three to four weeks until the plant is re-established.
Types of Poinsettias
Besides the traditional red bracts, newer hybrids have been bred in a variety of colors, including shades of white, cream, yellow, salmon, purple, burgundy, and pink. Note that some unusual colors, such as blue, are produced using dyes, and if the plant reblooms, bracts will be their natural color. Here are a few colorful varieties for your holiday décor:
- 'Plum Pudding': The first purple hybrid introduced to the market
- 'Lemon Drop': Cheery varietal with yellow bracts
- 'Jingle Bells': Red bracts splashed with creamy white markings
Common Pests & Plant Diseases
Like many houseplants, poinsettias are susceptible to a variety of diseases and pests, including gnats, whiteflies, thrips, mealybugs, and powdery mildew. If you notice signs of an infestation or illness, remove the affected area of the plant immediately and treat with an insecticide or fungicide until all signs of problems have disappeared.
How to Get Poinsettias to Rebloom
If you want to grow your poinsettia throughout the year and force reblooming for the next holiday season, you must follow a very specific process throughout the year. Achieving rebloom is not easy, so don't be disheartened if you don't succeed on your first try.
December to Early Spring
Water your holiday poinsettias, keeping them moist but not soaked. Then, starting in early spring, do the following:
- Gradually decrease waterings, allowing the soil to dry out between waterings. Be careful that the stem of your poinsettia does not begin to shrivel—this is a sign the plant is too stressed and is dying.
- In a week or two, when the plant has acclimated to this drying process, move it to a cool spot, such as the basement or a heated garage. Keep the temperature around 60 degrees Fahrenheit.
In mid-May, do the following:
- Cut the stems back to about four inches and repot your poinsettia into a slightly larger container filled with new potting soil.
- Water well and place the newly-potted plant in front of the brightest window you have, and once again keep it at a temperature of 65 to 75 degrees Fahrenheit.
- Continue watering whenever the surface of the soil feels dry and watch for new growth.
- Once new growth appears, begin fertilizing every two weeks with a complete fertilizer.
Come summer, move your potted poinsettia outdoors. Keep it in a partially shaded location and maintain your watering and fertilizing schedule.
In early July, pinch back each stem by about one inch to encourage a stout, well-branched plant. If left unpinched, the poinsettia will grow tall and spindly.
By mid-August, the stems should have branched and leafed out. Once again, pinch or cut the new stems, leaving three to four leaves on each shoot. Bring the plant indoors and place it near your brightest window.
Poinsettias are short-day plants, meaning their bud set is affected by the length of daylight. To rebloom, poinsettias need about 10 weeks with 12 to 14 hours of absolute darkness per day. You will have to artificially create these conditions and remain diligent.
At the very start of October, do the following:
- Keep your plant in complete darkness from 5 p.m. to 8 a.m.—any exposure to light will delay blooming.
- Use an opaque box or other material to block out all light, including artificial light. Many people place their plants in a closet, but if any light gets through cracks or if you open and use the closet, the exposure to light will affect the bud set.
- Move the plant back to the sunny window during the daytime and continue watering and fertilizing.
November and December
About the last week of November, stop the darkness treatment and allow the plant to remain near the window. You should see flower buds at this point. Stop fertilizing around mid-December. Keep watering and treat your plant the way you did when you first brought it home in bloom. If all has gone well, bracts should begin to show color.
Common Problems With Poinsettias
While caring for your poinsettia to encourage it to rebloom, be on the lookout for the signs of leaf and root rot problems described here.
Leaves Turning Yellow
Leaves will turn completely yellow or develop yellowness around the veins of lower leaves if the plant is stressed. There are many reasons for yellowing leaves:
- The plant isn't getting enough magnesium.
- The plant isn't getting enough molybdenum and needs soil pH to adjust to above 5.5.
- The plant is being over-fertilized.
- Powdery mildew is starting to form on the leaves and needs fungicide.
- The potting mix is too acidic.
- The plant is overwatered, low light conditions, and low temperatures.
If leaves have small spots with yellow halos, the plant has scab, which requires a fungicide application.
Stems and Leaves Turning Brown
Brown spots form on the plant in various places if it has canker, which might be helped by removing affected portions of the poinsettia. Stems will turn brown or black if the plant has root rot. Remove infected portions of the plant and try to repot the remaining healthier parts in clean soil and clean pots using sterile gardening tools. Apply a fungicide to the plant for protection.
Plant Leaves Falling Off
When a poinsettia defoliates, it doesn't spell good news and can lead to the death of the plant. It means that the poinsettia has serious canker or severe root rot from being underwatered, overwatered, or overfertilized. If some leaves are falling, the plant might also need a bit more light.
Are poinsettias easy to care for?
If you want to keep your poinsettia alive through to the next year's holiday and beyond, you will need to babysit the plant quite a bit. It's a job for an indoor gardener who appreciates a challenge.
How long can a poinsettia live?
If you are dedicated to keeping your indoor plant on a strict schedule for reblooming, it can live for up to two years, quite possibly three, or even longer.
How fast does a poinsettia grow?
An indoor poinsettia doesn't necessarily "grow," but it can rebloom. However, when grown in the wild, poinsettias are moderately quick growers and can reach between 10 and 15 feet tall.
My Poinsettia Has Lost Several Leaves. What is the Problem? Iowa State University Horticulture and Home Pest News.
Poinsettia Insect & Mite Management. Texas A&M University Horticulture Department.
Common Diseases of Poinsettia. Texas A&M University Horticulture Department.
“Poinsettias: Year after Year.” Nmsu.Edu, https://aces.nmsu.edu/pubs/_h/H406/