Nigel's Gardening Hints and Tips
Created | Updated Jul 13, 2009
Celebrate h2g2 With A Poinsettia
History
The Poinsettia plant has been around for a very long time and is mostly grown for Christmas time. It is native to Central America and it flourished in an area of Southern Mexico.
In the 14th-16th century, the Aztecs used Poinsettias (which they called Cuetaloxochiti) for medicinal reasons, mainly to control fevers. They also used the top red leaves to make a reddish dye for use in textiles and cosmetics.
In the 17th Century, a German Botanist called Wilenow found the Poinsettia growing through a crack in his greenhouse floor, and was amazed at the beautiful, dazzling colours. He decided to give this plant its botanical name Euphorbia Pulcherrima.
Then, in the 1820s, a man called Joel Roberts Poinsett became the United States' Ambassador to Mexico. This was a bad year, as it was during the time of a civil war. Joel was very interested in botany and upon a walk in the countryside discovered a beautiful plant with bright red leaves growing at the side of the road. He took some cuttings and propagated them successfully in his greenhouse. It was eventually named Poinsettia after his last name Poinsett, by William Prescott, who was also an interested botanist. Joel was the first person to introduce the Poinsettia into the United States and will be remembered for that wonderful achievement.
Growing of and Caring for Poinsettias
As it is December, garden centres and shops in the UK should be bursting with Poinsettias for our Christmas displays at home, or as presents.
A lot of people think that the coloured leaves (bracts) are the flowers, which they are not. The flowers are little, and usually yellow, in the middle of the coloured leaves of the Poinsettia. The coloured leaves have been forced to produce that particular colour by giving them a certain amount of light per day. I will discuss this further on.
Remember when choosing to follow these golden rules:
- Choose healthy looking Poinsettias that are not wilting or floppy.
- Make sure that the coloured leaves at the top do not have green around the edges as they will go all green very quickly.
- Make sure that the lower leaves are a nice, healthy green colour and are not yellowing and falling quickly.
- Do not purchase Poinsettias that have been left in plastic sleeves, as they will sweat and won't last.
- Remember to ask the check-out staff to wrap your Poinsettia(s) in a sleeve or other covering, as they do not like the cold and will go into shock very quickly.
When you get your Poinsettia(s) home, unwrap as soon as possible and place in a light place, avoiding direct sunlight. If you place on a window sill, make sure that the leaves are not touching the cold window.
Also, avoid cold drafts e.g. next to an open window or door. It is best to avoid placing them right next to radiators as well, because of the dry air which will shorten the poinsettia's life. The ideal daytime temperatures are 60-70 F ( and about 55 F at night, move the plant to a cooler room at night, if possible.
Make sure that there is adequat drainage in the bottom of the container and that the water can freely drain into a saucer or bowl. Check once a day, and water when the soil is dry. Avoid leaving any water in the bowl or saucer after watering, as this may cause the plant to suck too much up into its roots.
After it has finished blooming, it would be ideal to apply a houseplant fertilizer about once a month.
Poinsettia Re-flowering And Re-colouring
To get your Poinsettia(s) to re-flower/re-colour (leaves) is not easy and requires a lot of patience and care; however, it can be done and the results are usually exciting. Just follow these rules:
After the flowers have finished and the Poinsettia(s) are starting to die back (usually this is late winter to early spring time), then it is time to cut back each of the flowering stems to 4-6 inches in height. It is probably best to do this in February/early March time.
Re-pot into a larger pot (2-3 inches bigger than the one it is already in) with fresh compost and place onto a sunny window sill after watering in. This is best done in late spring/early summer. When all dangers of frost have gone, and temperatures dip no lower than 60 F, place your Poinsettia(s) in a shady position for approximately 2-3 weeks, so that it gets acclimated to the outdoor-life. After that, the Poinsettia(s) can be placed in a sunny, protected outdoor-bed, sinking the pot into a flower bed.
If we don't get much of a summer, then it is best to keep your Poinsettia(s) in your greenhouse, on a sunny but not scorching windowsill in your home, or a conservatory. Remember to check for watering every day. Once a week turn the pot so that the light gets to all parts of the Poinsettia(s) to keep the growth even on all sides.
To encourage a decent-shaped plant with a lot of flowers, the key-rule is to pinch out the growing tips, three times a week during the growing season. Two or three leaves should be left below the pinch as a guide. You should continue this until about the middle of August when the plant should have produced a nice shape, and have a good number of shoots.
Keep watering all through the summer, and feed every couple of weeks with a balanced feed.
How to get that lovely leaf colour and flowers
If you have your Poinsettia(s) outside, then it is important to bring them indoors before the night temperatures drop below 55 F at night.
Flowering is 'Photoperiodically'-induced in the Poinsettia. This means that the flowers will form according to the amount of light that is given during the day. The Poinsettia is a 'long-night-plant', and it is important no light is given, even a street lamp can stop flowering.
The Poinsettia's dark treatment must start from the end of September until about December 15.
It is best to cover with a piece of black cloth or even place in your wardrobe, making sure it doesn't receive any light after 5pm each day until approximately 8am the following morning.
When you see the floral bracts start to develop coloured leaves and also the flowers in the middle, it is not so important to restrict the light period. When the flowers have fully developed, they can be moved into the light, and no restriction will be necessary.
At this stage it is necessary to give as much sun-light as possible, avoiding drafts and dry air. There is also no need to feed fortnightly, once a month is enough.
That's all, enjoy your Poinsettia through the Christmas period!
Problems
Leaves dropping - The most common problem with Poinsettias is the shock of sudden change of temperature, the leaves will wilt and fall off. They do sometimes come back, but it usually takes until the next season for them to recover. Make sure the temperature is between 55-70 F.
Sticky, twisted leaves - This is usually because of an insect problem. Check all leaves, underneath as well, for any sign of insects. Treat with an insecticide if necessary.
Discolouration to the colourful top-leaves - This is the sign of too little light. Move to a lighter room.
Leaves shrivel and look dry - This is a sign that the room is too dry and the humidity is low. Move to a better location, misting if necessary.
The colour is fading in places - If the colour is fading in places, then this is usually a sign of over-watering. Make sure that you empty the saucer/dish every time you water.
Poinsettias come in a range of different colours of leaves (Bracts) to brighten up any corner of your home.
I have heard that we could be seeing a new type of Poinsettia out for the Easter month.
Nigel's Gardening Hints and Tips Archive