There are many rootstocks that can be used to graft Christmas cactus, but which one suits it best?

Today I grafted a Christmas cactus onto a night-blooming cereus, and it survived, but after the graft took, it grew extremely slowly, so I'm asking: is night-blooming cereus good for grafting Christmas cactus?

Grafting Christmas cactus onto night-blooming cereus is perfectly possible. The two are in the same family, and grafting them together can succeed; I researched and tried it before, and the graft can take, but if you use night-blooming cereus to graft Christmas cactus, it will grow extremely slowly. For one thing, the two are not very compatible. For another, the night-blooming cereus root system itself is not very well developed, so using it to graft Christmas cactus will make growth much slower. It would be better to just let the Christmas cactus grow its own roots and grow on its own, which is faster. If you also want to play around with grafting and find it rewarding, you can give it a try; it will definitely survive.

There are a great many "things" that can be used to graft Christmas cactus. Do you know which one suits it best?

Christmas cactus is generally grafted onto cactus or Pereskia; comparatively speaking, Christmas cactus and Pereskia have the highest compatibility. Grafted onto Pereskia, Christmas cactus will grow extremely fast. Cactus grafted with Thanksgiving cactus has very high compatibility between the two, and the Thanksgiving cactus will grow extremely fast. We know that Schlumbergera gaertneri blooms in spring; grafting it onto cactus will make it grow extremely fast, but when summer comes, if you don't manage it well, its leaf segments will continuously drop off. However, grafted onto Pereskia it grows a bit slower than on cactus, but its growth is very balanced. Also, cactus easily ages; after growing for a few years, its pads will age and be unable to carry out photosynthesis, and later the nutrient supply will not keep up, so the growth of the Christmas cactus is not as good as with Pereskia grafting, which can supply continuously, because the Pereskia root is very well developed and its lifespan is also very long, so for grafting Christmas cactus I suggest you use Pereskia to graft it.

Night-blooming cereus can be used to graft Christmas cactus, and cactus ball (globular cactus) can also be used to graft Christmas cactus; as long as it is a plant in the cactus family, it can be used to graft Christmas cactus. This is because they are in the same family, but after some are grafted, growth will be extremely slow. Our purpose in grafting Christmas cactus is to make it grow fast and bloom more, so when grafting it, choose as much as possible a cactus species with good roots, fast growth and a long lifespan to graft onto.