What do y'all pot Christmas cacti in?

[Fishkeeper]

What does everyone keep Christmas cacti and similar plants in? For that matter, does anyone grow them mounted?

I got a Christmas cactus last year. Not knowing that it was an epiphyte, I put it in regular cactus mix, although I kept it much wetter than usual cacti. Turns out, actual cactus soil isn't too bad for Christmas cacti, since it's well-drained. The plant's grown some, but has been a bit slow-growing so far, probably because it's not in optimal light.

I've repotted it into a much taller pot to allow for its starting to droop a bit, and I thought I'd try a custom mix. The goal is a reasonably nutritious soil with good moisture retention and excellent drainage, fitting for a plant that usually grows as an epiphyte. So, the ingredients are as follows:

2 large handfuls of the soil already in the pot, i.e. cactus soil.
2 large handfuls of a compost-based houseplant soil.
1 small handful of extra perlite.
1 large handful of thumb-sized fir bark chunks, chunk peat, and small bits of charcoal from my bag of orchid mix.

It appears to drain well so far. I'll test again when it settles a bit, and continue to check for moisture retention. If it compacts too much, I'll probably add more bark.

[WhiteRabbit]

I don't think they are too fussy ...
I've used all kinds of orchid potting media mixed up together - terrestrial orchid mix (when I had some), the heavy miracle gro orchid mix, spagh, perlite ... and/or cactus and regular potting mix, and perlite

They have very fine roots, and don't really want to be dry, which is probably why they aren't generally mounted - but, I bet that would be pretty cool!

[Fishkeeper]

They certainly aren't picky.

I had mine potted in cactus mix and in a tray of water, and it grew like that, seemingly with no complaints. I also gave some cuttings to a friend, potted in a mix of cactus soil, peat, and perlite, and that pot is doing well also. I'm just trying to figure out an ideal soil that also keeps it nice and moist.

Do you know if they have any specific moisture level needed, or is it just "not dry"? Mine was fine in soaking wet soil, but I'm just keeping it moist now, since I assume it would prefer that.

[estación seca]

These are really cacti, but not very succulent. They have been genus Zygocactus in the past. Most botanists now call them Schlumbergera.

The ancestors are native the the Brazilian coast from Rio de Janiero south (i.e., in the direction of increasing coolness.) They are native to misty, cool mountains. They also don't like heat. Sadly, several ancestor species are probably extinct due to city expansion.

They shouldn't get completely dry at any time. They will tolerate brief periods of drying during cool weather, but they will lose roots if dry during warm weather. They do well like African violets, evenly moist. During hot spells it is better if they are just moist. Roots rot if hot and wet. Because most people have a tendency to keep things wet when it is hot, they have acquired a reputation as being difficult to grow.

They tend to have very small and shallow root systems, so a small, wide pot is better than a deep pot, unless you tend to underwater. However, it is good to choose a pot tall enough that the natural pendant stems don't touch the supporting surface. Growing them mounted would be fine if you can water a lot, and have a humid environment. Most people grow them as house plants in pots.

Yes, being epiphytes, they do better with a very loose, open potting mix. Good quality potting soil is fine if you repot every 2 years.

Cacti don't even notice root disturbance when repotting. They don't mind at all if you use a hose to rinse off all the old potting mix before repotting. If you don't want to repot every 2 years, use mostly inorganic matter like pumice or large-particle perlite, with a top dressing of organic matter.

Almost all cacti like heavy feeding. These grow, and bloom, much better with much more fertilizer than orchids tolerate. Plants can at least double in size every year if grown well.

They are low-light plants, like Phals.

Blooming requires one of two things: completely uninterrupted, long, dark nights for 6 weeks; or 6 weeks of night temperatures 55 F / 12.5C or below. If you choose the long night method, remember that turning a light on near the plant just once during the winter will keep them from blooming. If the plants are kept cool at night, night length doesn't matter.

Single-joint stem cuttings will root in a bottle cap filled with water. Realize a lot of the hybrids are patented, and it is against the law to propagate them, even for personal use.

Their close relatives Rhipsalidopsis have radially-symmetric (actinimorphic) flowers, in the same color range. Plants look very similar, but lack the claws Schlumbergera sometimes have at leaf notches. Rhipsalidopsis bloom in spring, so they are often called Easter cactus. Night length and chilling are not necessary for blooming Rhipsalidopsis. These are less tolerant of warmth than Schlumbergera. Even in southern California, Rhipsalidopsis don't do well far from the coast. They seem to do well in Europe, the upper US Midwest and Northeast, and inside homes kept cool in summer.

[Lynn in Michigan]

I have one that my husband found in a pot with hardly any soil in it. I was busy with my orchids at the time, so the pot just sat in my greenhouse that year. I did pot it up the following year and I think I use cactus soil. It comes inside in the winter with my orchids and goes outside when they go out. It gets pretty much, all day sun. It blooms around Thanksgiving every year.

[Mountaineer370]

This thread is very timely for me. I have a couple of these, one of which was recently given to me and will need repotting soon. ES, thank you for your very comprehensive and informative post above!

[Ray]

Miracle-Gro Moisture Control potting soil.

[isurus79]

Oh crap, I put mine outside this summer not knowing they like cooler conditions. I'll have to bring it inside!!

[estación seca]

Originally Posted by isurus79

Oh crap, I put mine outside this summer not knowing they like cooler conditions. I'll have to bring it inside!!

If it's growing well outside, leave it. Night temperatures are more important. If it gets cooler nights it tolerates warmer days.

[isurus79]

Originally Posted by estación seca

If it's growing well outside, leave it. Night temperatures are more important. If it gets cooler nights it tolerates warmer days.

It seemed to be doing well, despite nighttime temps around 80 degrees. I brought it inside for safekeeping.