how to grow a christmas cactus
these care instructions are based on my experiences with schlumbergera truncata and its cultivars, other types can have different requirements.
christmas cacti care
- lighting: bright with some morning or evening sun
- watering: moist but not wet
- feeding: half diluted given monthly from april to september
- temperature: room temperature from spring to fall, approx. 10-17 °c/50-62 °f to get them bloom
- soil: a regular cacti mix
lighting
the christmas cactus thrives best in a location that is bright the year round with some morning or evening sun. winter sun is also tolerated. do not place in the midday sun in summer, unless you place it at least at a distance of 50 centimetres behind the window.
during summer it can be placed in a spot in the garden or on the balcony that is shaded from rain and the direct midday sun. it must get used to the sun not being filtered through a window pain.
if the temperatures start to fall to lower than 10 °c/50 °f lastingly, then it should be replaced indoors.
soil
the substrate should be permeable and contain minerals; a general mix for cacti is very suitable. anyone who is not in the habit of overwatering can also use a regular potting mix, which however, holds the water longer. it can be made more permeable if you mix in some clay granules.
watering
how often it should be watered depends on various factors, like for example the temperature, the substrate and the size of the plant in relation to the pot.
from spring to autumn i water copiously. the christmas cactus then holds as much water as the earth can take. any excess that leaks into the saucer must be removed after a few minutes as stagnant water can lead to rotting of the roots. the substrate can then be practically dry before i water again.
if water is needed can be gauged by the weight of the pot, wet earth is heavier than dry.
feeding
it can be fertilised with the usual green plant or cactus fertiliser, always in half the recommended amount. i add cactus fertiliser once a month from april to september. newly purchased or freshly repotted plants need no fertiliser in the first eight weeks.
reblooming
so that the christmas cactus forms its flowers it needs a quiet phase at temperatures between 10-17 °c/50-62. during this time i keep it as good as dry and unfertilised. if it should bloom punctually for christmas, then it must be placed in the cooler location from september onwards. during this time it should be only watered very lightly.
if the buds have reached a size of about one centimetre it can be placed in a warmer spot again. watering is not slowly increased.
with a bit of luck the christmas cactus will bloom twice a year. you can promote this by placing it in a cooler spot after flowering and keep it dryer again.
i only start with the fertilizer again when the new cactus joints form in the spring.