The shops are awash with poinsettias at this time of year in shades of red, pink and cream, the colourful bracts having taken an average of eight weeks to turn from green to red.
Garden centres, supermarkets, homeware shops and DIY stores all have them on display, but you need to be careful how you choose your festive poinsettia, says David Mitchell, plant buyer at Wyevale Garden Centres.
“When choosing a poinsettia, look for a strong-looking plant with bright-coloured bracts and deep green leaves all the way to the base of the pot,” he advises.
“A UK-grown plant is by far the best. We grow them cooler and allow them more space, making sure they are tougher for the customer. Check if the retailer is displaying them in a warm, draught-free place and never buy a poinsettia which is being sold outside or near to open doors.”
Once your plant’s back home, don’t place it on a porch or in a conservatory, because poinsettias don’t like draughts. You’re better off putting it in a warmer room like the living room, but not near a radiator.
“The worst place is a draughty window sill especially if you draw the curtains on them leaving them in the cold space,” says Mitchell. “These plants like good light, but are not so demanding for high light as many other house plants. The main point is to keep them warm, between 15 to 20 degrees, and away from draughts, avoiding sudden temperature changes.”
Poinsettias should be watered as the compost begins to dry out. Don’t over-water them or the leaves will drop off and don’t leave them to dry out completely or they may not recover.
After Christmas, allow the poinsettia some time to rest and become almost dormant by reducing watering. When bracts begin to look old and tired in late winter or spring, don’t worry if the leaves droop or fall.
In June, prune the plant back to approximately a third of its size. Repot, feed and water at this stage regularly to build a well-shaped plant.
New growth will sprout, so stand it in good but not bright light, water regularly and apply liquid fertiliser every two weeks throughout summer.
From the end of September, ensure the plant has natural day length rather than any artificial light. Poinsettias, which are cultivars of Euphorbia pulcherrima, set bracts and flowers in response to short days. Most will need to have light excluded to ensure 14 hours of darkness out of 24 for eight weeks during the run-up to Christmas.
Once there are more hours of darkness than light, the plant will begin to change colour. If you begin the initiation process at the end of September, you should start to see a subtle colour change by mid-October and the full transformation by the end of November.