There are some plants that are inevitably associated with the holiday season and for me, these are the poinsettia and the Christmas cactus. I like these flowers and I take advantage of them every year to decorate the house as winter approaches. But can they be grown outside too? Is Christmas cactus afraid of frost? How to maintain it during the cool period to make it bloom again and avoid soft leaves? These are the answers, according to certified urban agronomists.
Given that a plant has ‘Christmas’ in its name, its resistance to cold is only logical, isn’t it? Well, not quite, because ours is also a cactus! And although it does not look like a ball with a thousand spikes, it still bears the peculiarities of this genus of plants. Anyway, don’t imagine a desert where temperatures exceed 40°C as its ideal habitat… In fact, this fleshy plant only forms buds when the ambient temperature is relatively cool. So is Christmas cactus afraid of frost?
The short answer is yes, Christmas cactus can’t stand frost and there’s not much you can do to stop it. Like Poinsettia, the Schlumbergera is a tropical plant and the warm and humid conditions of its place of origin, the Brazilian forests, are the best for its development. Of course, reproducing them exactly is not possible, but the varieties that are grown in pots almost everywhere in Europe have adapted to the environment that our homes offer during the coldest months of the year. But what about growing them outdoors?
Alas, Christmas cactus could only survive outdoors in areas with a mild Mediterranean climate, for example Southern France and the coasts of Corsica. Even there, putting it in the ground is not exactly a good idea, if you want to enjoy it as a perennial. The main reason for this is that although the temperatures in these areas rarely drop below zero in winter, the Schlumbergera can only withstand temperatures of up to 10°C, no less.
Potted Schlumbergera to enjoy all year round
Of course, planting a Christmas cactus in a pot from cuttings can be done anywhere in our home and it is a very good approach to growing it. Cutting is done in the same way as for the jade plant and most succulents. In short, we take leaves, let them dry out a little, put them on the surface of a pot of soil, sprinkling them sparingly with water and let them form roots, which can take a few weeks.
In conclusion, it can be said that the typical “Christmas” plants are not nicknamed that because they are hardy and can tolerate the outside temperatures of late December. It is during this period that they are expected to flower and they are at their peak, but it is only inside the house where temperatures are around 20°C throughout the year so they can survive and thrive.
The Christmas cactus is therefore hardy for a cactus, but generally not very cold tolerant. It doesn’t like draught or temperature fluctuations, which means that moving it from the garden and putting it next to the fireplace would be a terrible idea. In fact, it’s when the temperatures drop below 12-14°C and the days start to get shorter that your Schlumbergera will bloom.
SOS: My Christmas cactus isn’t blooming! Why?
Yes, the plant is sensitive to the length of day and night which influences the period of its flowering! So, if you are wondering how to make your Christmas cactus bloom again year after year, the first thing to do is to provide a cool atmosphere (but not below 10°C) and above all a cycle of 16 hours of darkness and 8 hours of light out of 24. This last factor is the key to beautiful winter flowering!
In late spring and early summer, it is completely acceptable to take the plant outside and place it on a spot sheltered from the wind. This is done gradually so that the Christmas cactus can adapt to the new conditions. Be aware that if you leave it outside too late in the fall, you can expect cold damage. Ok, Christmas cactus is afraid of frost, but can you save it once exposed to it?
Can we recover a Christmas cactus exposed to frost?
When your Schlumbergera faces freezing temperatures, the water stored in its fleshy tissues will freeze causing it to expand and damage leaf and stem cells. Once the water thaws, the tissue shrinks, but the cell walls are already damaged and they can no longer hold their shape. This results in limp leaves, yellow or brown spots, etc.
Dealing with cold-exposed Christmas cacti requires patience. First, remove any tissue that looks badly damaged or rotten. Keep the plant lightly watered, but not soggy, and place it in an area of around 15°C. If it survives six months, boost it with half-diluted houseplant fertilizer once a month during the months of active growth and stay optimistic!