While some who don't do well with houseplants may fear that the gift orchid will have popped its clogs by the time the friend or relative who gave it to them makes a return visit, in fact they are pretty easy plants to keep given the right environment and light.

Moth orchids (phalaenopsis) are among the most common of the species given at Christmas, usually with one flower spike but sometimes with more, to bring a burst of vivid colour to a windowsill in shades of
pink, white and red, with various markings on the flowers.

Flowers may appear at any time of year on an orchid. They have rambling roots which spread across the surface of the pot, searching for nutrients. The roots contain chlorophyll and produce energy from light, so growing them in open lattice baskets or clear pots is better. That way you are also more likely to notice if the roots are wet or dry.

Orchids need bright light, but not direct sunlight. They benefit from extra artificial light in winter to encourage flowering, in an ideal room temperature of around 20C (68F) and phalaenopsis don't like the cool nights favoured by some other types, so don't let the temperature inside fall lower than around 18C.

I've had a moth orchid on my kitchen windowsill which has flowered pretty consistently for around a year. Only in November did the last flowers finally drop. All I've done is watered it once a week by sticking the whole pot in a sink half filled with tepid water for a few minutes, without allowing water to sit on the leaves, before putting the pot on the draining rack for around half an hour to allow all the excess to come out, and then putting it back in its container.

Others simply use a watering can, but however you do it the secret is not to leave the plant stand in any water once you return it to its pot, as one of the main causes of orchid death is root rot.

Also feed the orchid with specially formulated liquid feed once a month to keep it healthy.

Reduce watering in the winter to keep the plant almost dry and regularly spray the leaves (but not the flowers) with soft water.

After flowering, cut the stem back to the second lowest bud to get a new flowering shoot, or remove the old stem completely to encourage a more shapely new shoot.

Like most houseplants, moth orchids do need a rest period to build up energy again. They can simply be put in a room with a slightly lower temperature than normal for a few weeks in autumn. Don't be tempted to cut off the roots growing outside the pot, as they are aerial roots which absorb moisture from the air, keeping the plant healthy.

You can keep moth orchids in the same pot for a couple of years and they should produce one or two new flower spikes every year.

When their roots become really crowded you can repot them using orchid compost, which contains bark and other good draining material. The new pot shouldn't be much bigger than the old one and you can trim dead roots back to their base and water lightly from the top to settle the orchid into the new pot, using tepid water.