Protection and light
Plants are vulnerable to plants, draughts and overwet compost at this time of year. Keep tender plants at or above their minimum temperature. You should move cold-sitting plants to a warmer spot at night, making sure they get some light during the day. Artificial light is beneficial, but keep foliage away from direct heat and avoid the hot, dry air of centrally heated houses.
When the compost is consistently too wet, the roots will rot. If this happens, tip the plant out of its pot and wrap its rootball in several layers of newspaper for a day or two. Change the paper when it is saturated. When the compost has dried out slightly, replace the plant in its pot.
Try to provide a minimum temperature of 7°C (45°F) in the conservatory. Insulation can help to reduce heating costs.
Feed plants only when growing strongly or when they are in bloom.
House plants – overwatering
Most house plants will collapse if overwatered. You may be able to save an affected plant by wrapping the rootball in absorbant paper for a day or two. Cover the roots and change the paper if it gets too saturated.
Keep flowering plants purchased at Christmas in a cool room and deadhead azaleas and primulas regularly to extend their period of flowering. Modern poinsettias last a long time in flower. After flowering cut back their stems to 15 cm (6 in) from the bases. Keep the compost almost dry until May.
Bring pots of polyanthus which were potted up in the summer indoors and keep them in a cool room at a temperature of no more than 10°C (50°F) until they are about to flower.
Sow seeds of gloxinias and streptocarpus in a propagator over the next two months so that they will make plants large enough for display by late summer.
Indoor bulbs and corms
Increase watering of hippeastrums planted up last month and keep them warm and moist.
You can extend the flowering period of cyclamen and lachenalias by keeping them in a cool room and deadheading them regularly.
Bring pots of forced bulbs still in light, cool positions into the warmth when they are ready to flower. Keep the compost moist and deadhead when blooms fade. You can keep them to plant out by feeding them half-strength tomato feed.
Keep these in bright light at a minimum winter temperature of 15°C (60°F). Bromeliads such as the urn plant (Aechmea fasciata) and billbergia will survive at 7°C (45°F) but will become dormant.
Mist air plants once or twice a week, holding a hand-held mister about 30 cm (12 in) away from the plant. Mist lightly; do not make them too wet.
Cacti and other succulents
Rest these over winter at a temperature between 7 and 10°C (45 and 50°F). Ensure that the plants receive plenty of light while avoiding overwatering.
The compost should not be allowed to completely dry out even if the orchids are in active growth. During the dormant period, keep dormant plants just above their minimal temperature. A number of popular orchids can be overwintered successfully at a temperature as low as 10°C (50°F).