Visit any commercial greenhouse operation at this time of year and it will be a dazzling display of colour. There will be bench upon bench of red, pink, cream, yellow, white or salmon-coloured poinsettias.
These plants have been quietly growing in the greenhouses for over three months. Poinsettias arrive as cuttings or rooted plugs. They are potted, a predetermined number per pot and grown.
It takes timing and care to produce a well-rounded, leafed-out poinsettia plant in a pot. Poinsettias are native to Mexico and Central America where they flourish in moist ravines. Given the correct growing conditions these plants reach a height of 10 feet (3 metres). To grow the plant and contain its size is often a feat in itself.
Once potted, greenhouses painstakingly control growing conditions of these fussy plants. The light and dark cycle is controlled to ensure that plants will produce buds. If the pattern is disturbed, the plant will not flower and the bracts will not become bright and colourful. Nobody will buy a non-flowering poinsettia.
Poinsettias would grow much higher, and be less bushy except that greenhouse workers pinch the terminal buds back which force the lateral buds to grow and produce their own colourful bracts and flowers.
Plant spacing, fertilizer, temperatures, light and growth inhibitors all play a role in producing the well-shaped, multi-flowered plants available for purchase.
Poinsettias are available from greenhouses, grocery stores and big box stores. They are also available from many different community groups that sell the plants as a fundraiser, with a percentage from each sale going to the community group.
When purchasing a poinsettia choose one that has many branches or a number of plants in one pot. Leaves should cover all the stems from the pot to the bracts. Do not purchase a plant in a sleeve unless you can tell that all the branches are still attached to the main stem. Not examining the plant carefully or leaving in the sleeve is a mistake as poinsettia branches are brittle, making them subject to breakage if they are not handled carefully.
Poinsettias come from a warm climate and they do not like the cold. In fact, the plants tend to drop leaves when they are exposed to the cold or even a draft.
Double wrap the plants when they are being transported in cold weather. Minimize the time they are exposed to the cold by making sure the vehicle is warm before transporting the plant. It is best to transport when temperatures are above freezing.
To keep the colourful bracts as long as possible, place the plant in indirect, bright light. Make sure the plant is not in a warm or cold draft. They should not be close to any window.
Water the plant when the top soil is dry. If the pot contains more than one plant, ensure that water reaches each root system.
The plant will drop leaves if it is dry or too wet.
If the plant is not in an ideal environment it will drop its bottom leaves.
Poinsettias were once thought of as very poisonous but that was proven to be false. The milky substance that flows from the plant when a stem is broken or leaf removed can irritate the skin causing rashes but it is unlikely to kill a person or pet even if it’s eaten.
Linda Tomlinson is a horticulturalist that lives near Rocky Mountain House. She can be reached at www.igardencanada.com or your_garden@hotmail.com