Known as the Christmas Cactus, Zygocactus truncatus is one of the most interesting of indoor plants, being easily grown and propagated, and its attractive cerise-pink flowers, which are borne in winter, make it one of the best of all indoor plants; and preferring semi-shade it could be more widely grown. It is a cactus, being one of the Epiphyllum group, the plants being almost spineless and having flat, fleshy stems. In their natural state they are to be found growing on trees in the forests of South America, where they are able to survive long periods without moisture.
The zygocactus forms its hose-in-hose flowers at the end of the stems. These are composed of numerous flat segments and are produced in weeping fashion which makes this an excellent plant for an indoor hanging basket. It is also attractive if grown in a size 48 pot placed on an inverted pot where its drooping habit can be fully appreciated.
More than for any other form of cactus this plant requires a soil containing plenty of humus. The compost should be composed of 3 parts fibrous, 2 parts and 1 part sand, and never at any time allow the compost to dry out. Unlike the desert cacti, the plants do not require lime. Throughout summer and until the plant has finished flowering towards the end of winter, the compost must always be kept moist and during summer the plant will require plenty of moisture. After flowering, it must be given a rest period of several weeks, but this does not mean that all moisture be withheld. Give sufficient to keep the plant alive, then, as the weather becomes warmer, the amount of water is increased. Take care not to water the plant itself for moisture remaining on the segments in winter will cause decay, whilst during sunny weather scorching may occur.
A minimum temperature of 45°F (7°C) should be provided but one nearer 50°F (10°C) will make for a better flowering display and humidity may be encouraged by standing the plants in saucers containing damp moss.
Propagation is by the removal of the segments at the joints and inserting into a compost of peat and sand. They will root quickly during early summer, the rooted segments being planted into small pots for growing-on when they will come into bloom by the year end.