These plants have been much neglected of late, despite their having the largest and most spectacular flowers in the cactus world (perhaps even the best flowers of any flowering plants). This neglect is probably due to the amount of space required for some of the plants in the past. This no longer holds true as many new varieties have been bred in recent years which are much smaller growing, and many basket varieties with a superb flower colour range are now available.
EASTER CACTIThe Easter Cacti are now known as Rhipsalidopsis or Hatiora.
These produce their flowers in April and May, lasting for about six weeks, and will sometimes flower again in the autumn also.
Cultivation is as for the Epiphyllum above, except that they should be kept cooler during the resting period from October until the buds become visible in the spring. Watering and feeding are then gradually increased and continued until late autumn.
Easter cacti are more prone to segment drop on drying out than other epiphytes when watering is not regular.
Christmas cacti are probably the best known and most popular houseplants in the world. They are popular because they are so easy to grow in the house and produce many flowers at a time when flowers are rarely seen.
Today, the Christmas cacti we see in the shops (- their Latin name is now Schlumbergera although they used to be called Zygocactus ) are all cultivars (horticultural hybrids) obtained by crosses ( or chance "sports") between the recognized nine species discovered in the wild.
Cultivation as for Epiphyllum above.
To guarantee flowering - Christmas cacti are "short day/long night” plants. They will only start to produce their buds when dark winter nights are longer than 13 hours. They must therefore be put somewhere where they get "natural" long nights
To overcome this problem, plants can be put outdoors from August to mid-September (in a shady place), or in any room not used for long periods at night. Once buds are visible, plants can be returned to their usual position in the house, and will develop flowers normally, whatever the light regime.
Plants will tend to flower more freely if tightly potted, so don't use too-large pots.
Temperature - Varieties vary, but most will flower at Christmas if kept at 50 to 55 deg. F (10 to 12 deg. C) from September to December. Kept at their advised minimum of 40 deg. F (5 deg. C) some may not flower until February.
To obtain pure flower colours with the white & yellow cultivars a minimum of 60 deg. F (14 deg. C) is needed (only from bud-set until flowering!) otherwise they will be tinged pink or orange.