(Editor's note: This article was originally published on Dec 12, 2007. Your comments are welcome, but please be aware that authors of previously published articles may not be able to respond to your questions.)
Poinsettias are members of the Euphorbia family, though they certainly don’t look like the typical Euphorbias one associates with the desert or Africa, where most of the Euphorbias we are familiar with come from. Euphorbias are native to nearly all the continents and this one, Euphorbia pulcherrima (means very beautiful Euphorbia), is a Mexican native. Like all Euphorbias, it has a sticky, somewhat noxious white sap that can be irritating to the skin or eyes. Toxicity of this species has been very exaggerated, however, and at worst it can cause some oral irritation or stomach ache if eaten.
These plants were already being used as medicinal and ceremonial plants in the 1300s by the Aztecs. Just about 100 years ago some people (namely the Ecke family in California) started to grow and sell these plants as outdoor landscaping plants and as cut flowers. It wasn't much later when these plants were starting to be propagated in large numbers in greenhouses. Now just about every state produces Poinsettias commercially, though California is still, by far, the major producer of this plant.
These are shots of the Orange County College poinsettia greenhouse operation in the fall. The college makes a lot of money to help fund education and horticultural projects with their yearly sale of poinsettias.
Poinsettias are shrubby, leafy plants with weak stems, that eventually develop into spindly, woody stems up to 10’ tall. Their leaves are bright to dark green and the flowers are itty bitty yellow structures in the late fall and winter. The red ‘flowers’ one associates with this species are really specialized leaves called bracts that appear when it is time for the plants to flower. It is these bracts that make these plants so beautiful. The flowers themselves are fairly insignificant.
Outdoor plant at the Huntington Gardens in January
Stems of an outdoor plant, southern California (left photo). Right photo is a close up of an outdoor bract (red leaves) and the yellow-gold flowers in the center (photo by careyjane)
There are over 100 varieties today of Poinsettia, most red with various leaf shape, size and number, as well as yellow to white and pink varieties. The red simple leaf form is the natural form, though, and it seems this form is about the only one that does reliably well as a landscape plant. All the cultivars seem less sturdy in terms of surviving as outdoor landscape plants.
3 varieties photographed by Happenstance (from left to right): Carousel Pink, Lemon Drops and Strawberries and Cream
The Sonora White Glitter and Winter Rose Dark Red are Henry photos, while the Cinnamon Star on the right is from Kniphofia
Freedom Salmon, Orange Da Vinci and Prestige Red, also by Kniphofia
Snowcap White, Winter Rose Marble and Lemon Snow, also by Kniphofia
Cortez Burgundy and Premium Apricot are photos from Todd_Boland
For those interested in celebrating this plant, December 12th is official Poinsettia day in the US.
Indoor/ New plant care:
When acquiring a new plant, it is best to start with the healthiest one possible. Look for a large crown of leaves/bracts, short stems and with green leaves down to near the soil line. Do not pick anything with wilted leaves, weak or bent stems, sloggy or super-dry soil or crammed into a sleave in such a way that it looks like it’s been there a long time.
this is a relatively healthy looking plant with leaves to the soil level
Poinsettias, though able to survive outdoors in California with bizarre weather variations including freezing cold winds, hot, drying winds a few days later, intense rainy periods, prolonged drought, baking heat and inconsistent garden care, are quite sensitive right out of the greenhouses, particularly in flowering mode. So it is best to avoid getting them blown about much, avoid direct sunlight at first (they can be happily acclimated to some full morning sun later) and temperature extremes. These new plants prefer temperatures in the high 60s or low 70s (Fahrenheit). Temperatures below 50F will usually cause them to lose all their bracts and stop flowering.
Water only when the soil is dry on the surface but before starting to dry out all the way (these may be Euphorbias, but they are not that drought tolerant, particularly as potted plants or in this sensitive time period). If purchased in a container that collects water (most poinsettias are sold that way to keep water and soil from leaking all over you, your car and house), remove those items from around the pot. Water should flow through easily and these plants should never be sitting in standing water. If your plant is on a pot tray, be sure all the water drains through, and then empty the tray. They rot far too easily.
these plants in the nursery get watered at least once a day, but it is warm out still and they have no catch basins below
The brighter the light these plants are kept in, the better, but without being in direct sunlight. After this flowering season one can gradually get the plant acclimated to full morning sun in a window, and once adapted, they will become even hardier and grow better. Prolonged darkness will cause leaf drop and an end to flowering.
Fertilization is something best NOT to do while your poinsettia is flowering. This will also cause flowering to end prematurely, though it probably won’t hurt your plant as long as you use a well-balanced, water-based fertilizer.
Keep your plant away from heavy drafts, fans, and air-conditioners. These plants are very sensitive to these minor fluctuations while flowering.
Keeping your Poinsettia
Now that you have managed to keep your precious new plant alive through the holiday season, you will notice it starting to lose the pretty bracts, no matter how well you take care of it. This is normal. Some recommend a period of ‘rest’ at this time- like putting these plants in a cool cellar or dark place until spring time. Temperatures for this rest period should be at or under 60F, but not over. Keep watering it regularly, but try to keep it on the drier side now (not bone dry, ever, though!). Bring them back of out 'resting' in spring.
By spring time these plants benefit from a pruning- cut them back to about 6"-8”. Water as before, but now you can start adding in some water-soluble well-balanced plant fertilizer every 2-4 weeks. You should notice some healthy new leaves and stem growth within a month. If warm enough outdoors (no risk of frost) it is best to take these plants outdoors for the rest of the spring and summer. If you want your plants to remain bushy and compact, you will need to prune repeatedly every few months. But do not prune near the end of summer and not again after that until the following spring.
outdoor plant after its first year, did not get pruned, and now it is leggy and lean looking, not the look one normally looks for
Sometimes repotting into a larger pot is recommended, particularly for crowded plants. It is recommended to only go up a bit (4” at most) in pot diameter. Over potting can lead to root rot.
If you live in a climate with little or no frost, summer is the time to plant your plant outdoors. Remember that although this is a Euphorbia, it is not a desert plant and shouldn’t be put in your cactus garden (unless you water it a lot). Evenly moist soil that drains well is best, and in a situation with at least half day sun (these plants get leggy and weak in shade).
Planted plant in early spring in my yard on left, and same plant 6 months later, early fall
However, this Early Red variety was also planted out in spring, and the dead sticks are all that remained by summer... much wimpier as a landscape plant!
Outdoors these plants normally flower in the late fall or early winter. However lighting is very important and even artificial lighting from streetlamps or other sources can affect blooming, even prohibiting it. Outdoor plants are impossible, really, to ‘time’ blooming with Christmas, but they should flower naturally at least close to holiday season, barring some lighting interference.
To ‘re-bloom’ indoor plants:
Starting October 1, these plants should be moved into a totally dark area (room or box) overnight at least 12 hours at at time, with temps in the 60s-70s. If kept in a dark room be sure no one goes into it accidentally overnight and turns on a light, or it could adversely affect their flowering schedule. In the day they need at least 6-8 hours of bright filtered or direct sunlight. Temperature ranges and lighting times are critical for blooming over the holiday season. Variations from these parameters could make these plants bloom too late, drop bracts too early, or not flower at all. Water and fertilize as before, but stop the fertilization schedule as soon as signs of bract of flower formation begin. If everything goes well, you will have plants that look like they did the season before, but perhaps even busier.
If you have successfully kept your poinsettia for two seasons, it will be time to try to propagate your plant if you want. Most poinsettias originate from cuttings, and one can either purchase these cuttings, or make cuttings of your own.
Just as was done the previous year, one should prune their potted plants back. This time, however, it might be better to do it in a bit warmer season, like early to mid summer, but no later than the end of August. Daytime temps for growing cuttings should ideally be 85F at the most, and 72F at the least. If this does not match your climate you will need to move your cuttings into a greenhouse, or in and outdoors regularly to keep them from being overheated, or get too cool.
Cuttings should be about 3”-4” in length and have 3-4 healthy green leaves on them. You do not need to allow the cuttings to dry a few days and apply rooting hormone on them (not necessarily essential).
Root the cuttings in slightly moist, well draining, highly organic soil in a 4” pot and keep this soil evenly moist for a few weeks until new growth is seen. One recommendation is 30% peat moss and 70% course sand (not super-fine playground sand). But many well draining, organic media will do. Just try to be sure the soil is clean and free of organisms (never re-use soil for cuttings). Don’t just shove the cutting into this soil, but make a hole with your finger and stick it in gently, pushing the soil around it to fill in the hole. If there are leaves on your cuttings, mist the leaves daily, if not twice a day (except in the most humid of climates). Watch carefully for white fly and fungus gnats as they can be particularly hard on cuttings. Do not fertilize cuttings until signs of new growth are seen. Lighting should be partial sun/partial shade avoiding hot afternoon sun. Move cuttings into a protected area during rains or they could get too moist and rot.
Once new growth is seen, misting is no longer necessary, and fertilization can begin. Move plants to 6” pots and now you can put more than one plant per pot. Now you have just doubled the number of plants you have!
Though many insects/mites can infest these plants, by far the most common pest encountered is the white fly. These are small, very white fluttering insects (resemble miniature moths). Usually you find these on the undersides of the leaves. This insect is particularly hard to eradicate, but fortunately they rarely do much damage to this species of plant unless they are present in massive numbers. White flies can be physically hosed off, and insecticidal soaps help prevent their return. Remember they live on the undersides, so hosing should be from below, ideally.
two view of white flies on plant. The third photo is evidence of white fly- a wavy, spiraling white area where the flies lay their eggs
Spider mites are mostly a problem of low humidity indoor situations but rarely a severe problem in Poinsettias. Mites can also be treated with insecticidal soaps. Spider mites are pretty hard to see with your naked eye, but evidence for them is a fine, pale speckled pattern on the leaves, usually near the tips (where the ‘juices’ have been sucked out of). It takes a lot of spider mites to suck the juices out of a poinsettia leaf.
Mealy bugs are a relatively dangerous pest, but easy to see and fairly easy to control. These are the largest of the pests and look like blobs of sticky, flat, white cotton about 1/8” long. Alcohol swabbing and/or insecticidal soap takes care of these nuisances. If you see these, also look for ants as they may be who are bringing in the mealy bugs. Control for ants as well.
Fungus gnats are themselves pesky annoyances, but their larvae can damage the roots. Fungus gnats are tiny brownish, fluttering insects about the size of a head of a pin and can be seen flying about the soil. These are usually very easy to get rid of with some dousing of insecticidal soap.
For more information about Poinsettia care, see these web sites: