Christmas cacti are succulent plants of Brazilian origin, belonging to the genus schlumbergera (also called zygocactus, or Ephiphyllum); there are about six species of schlumbergera, characterized by an autumn or winter bloom. They are plants that produce short stems, which are divided into long branches, erect, arched or hanging, made up of flattened, oval-shaped, fleshy sections; the articles end with small points, or are completely rounded, dark green, they tend to change color as the amount of light changes: if the plants are placed in an excessively dark place they tend to become light green, if instead we position the schlumbergera in full sun the branches become pink or reddish. In the nursery we usually find only hybrid varieties, which can be divided into two large groups; the schlumbergere are very appreciated for the long flowering, in autumn and winter, from the areolas present at the apexes of every single article, large flowers bloom from the fleshy petals, with very evident pistils, of red or rosé color. There are hybrids with particularly colorful flowers, or very large ones, the schlumbergas with white flowers streaked with pink are very common.
To this group belong the hybrids obtained from the schlumbergera truncata, which have zygomorphic flowers, or the upper part appears different in shape than the lower part; the flowers bloom in autumn, and are placed horizontally with respect to the ground. These schlumbergas typically have arched branches, although there are varieties with upright branches. The typical characteristics of these hybrids can be found at the end of each single article, which ends at the sides in two small fleshy tips.
The Schlumbergera varieties originated from the hybridization of Schlumbergera russelliana belong to this group; Contrary to what happens for the varieties of the truncata group, the articles of these schlumbergers do not have small points, but are rounded. Also these schlumbergere can have arched branches, but more often they are completely falling or erect. The flowers are hardly zygomorphic, but they are generally completely symmetrical, and are carried erect and not horizontal.
The schlumbergere belong to the cactus family, as happens for most of the succulent plants of the American continent; despite this, they differ greatly from what is commonly called a cactus, and not just because of the shape of the stem divided into segments. In fact these cacti grow in the wild in the mountainous areas of Brazil, where there is a fairly mild climate, with high humidity; they also develop at the foot of tall trees in the forests, or even in cracks between the rocks, where they can enjoy small amounts of direct sunlight. So, although they can withstand conditions quite different from the ideal ones, they do not survive if grown like most cacti, or with little water, a constantly hot climate and lots of sunlight. The schlumbergere are epiphytic plants, which do not require large amounts of soil; they are cultivated in relatively small pots, possibly shallow, filled with soil for acidophilic plants, mixed with universal soil and leaf soil (or even sphagnum). The pots should be kept in a partially shady place, where they can enjoy a suffused brightness: the direct light, especially in the hottest hours of the day, causes the reddening of the stems. Watering will be regular throughout the year, in order to keep the soil slightly humid, but without soaking it and without leaving it dry for long periods of time; every 12-15 days we mix the water of the fertilizer with succulent plants, poor in nitrogen and rich in potassium. These plants can withstand temperatures a few degrees below zero, for short periods of time; but they are usually grown at home, where they show that they grow and flourish better if they are kept in a poorly heated room, or in a stairwell, where the climate is mild enough, but not warm. Plants kept constantly in the house tend to produce less and less flowers from year to year, as they need a cool period, with a few hours of light, to start producing their beautiful flowers.
Pests and diseases
Excessive watering can cause the rotting, total or partial of the stems; as soon as the plant shows a soggy appearance, as if it had "fainted", we cut all the healthy stems and use them as cuttings, because the rot from the roots quickly goes back to the whole plant. Even drought can be a problem for schlumbergers, especially if prolonged: a poorly watered plant takes on a wrinkled appearance; if the water shortage is of short duration, it is sufficient to water because the stems return to their turgid and fleshy appearance. In spring it can happen that the aphids nest in the flowers.
Propagate the schlumbergera
This cactacea is characterized by flattened stems, similar to large leaves, divided into segments; every single segment can give rise to a new plant, and it also happens naturally that the falling segments produce roots if they remain in contact with the ground. Given that the varieties present in the nursery are hybrid, and that these plants are pollinated by hummingbirds, not present in Italy, stem cutting is one of the fastest and most convenient methods of propagation. Stems are taken in spring, and the various segments that compose them are divided; we avoid choosing a very old stem, or a newly sprouted one, and we prefer healthy and meaty stems. Every single segment will be buried for about a quarter, in a rich soil; after about a couple of days we begin to water, keeping the soil just damp, until we see that the stems begin to sprout.
Christmas cactus - schlumbergera: How to water the Christmas cactus
As we have already said before, the Christmas cactus is a plant that must be grown in the apartment because it needs temperatures that are not too low to vegetate properly. The ideal temperatures for this plant are in fact always above 20 ° C and we will have to take this aspect into account when growing it.
Being cultivated in the apartment, this plant in winter does not undergo a great evapotranspiration and with watering it is necessary to take particular care to avoid exaggerating with the quantities of water.
Let's water the Christmas cactus once in a while and make sure that the soil has time to dry between one watering and another. A constantly moist soil can cause radical problems, such as root rot problems or other pathologies favored by the presence of a humid climate such as mushrooms.