Growing pains

But without man’s help, Euphorbia pulcherrima would still be just another plant getting on with its life thousands of miles away from the UK. It’s only because we have tinkered with its make-up that it now reigns supreme as the most popular living Christmas present.

In its home territory, it is still tall and leggy (you have to look up to it) but in Britain it is now a compact, bright and easy-to-accommodate pot plant.

But it’s not really a flowering plant – those great, red “flowers” are, in fact, nothing more than glorified leaves.

But that doesn’t put off millions of people who every year buy one in December – and then throw it away early in the new year. Because while looking after a poinsettia should be relatively straightforward, many people end up with plants which would be happier on the compost heap.

All these specially-produced euphorbias want is a reasonable temperature (between 55-60F), plenty of light (but not direct sun), water, an occasional misting of their leaves, and perhaps a little food when they are at their peak.

Over-water and the leaves will wilt; under-water and the leaves will wilt and turn dry; dry air will also turn leaves brown and encourage red spider mites to take up residence; and leaving a plant behind the curtains on a cold night can also have a devastating effect. Just remember to bring it into the room when you shut out the darkness.

There’s not a lot of point in trying to keep a poinsettia from one year to the next, although that doesn’t seem to stop people from trying. If you want to know how to do it – and you want the challenge and are prepared to spare the time – read on.

After leaves have fallen, cut back the stems to 4in. Let the compost dry until May when you should start to water.

Then repot, feed and remove some growth to leave five or so new stems. From the end of September, cover the plant with black polythene from evening till morning so that the plant has 14 hours of darkness each day for eight weeks.

Then, treat it normally. It will be taller than before because, originally, it will have been chemically treated to make it squatter and bushier.

It’s a lot easier to buy a new plant every year.