How should I proceed with this cacti

Question

I have one cactus for about 5 years now, and since then it grew from about 3 cm to considerable size. I am watering it every 20 days and it is not exposed to direct sunlight. But I was always puzzled should it look like this , I have never seen similar cactus because it has long branches and it looks to me that it cannot stand straight by itself.

When I water it the branches tend to straighten and it starts to grow. And then it curls again until I water it again.

20 days ago I took a branch that curled and fell off and poke it directly into the soil for cacti, keep it in the direct sun and water it when the soil is dry, since it was sunny I water it every 5 days.

So after 20 days it went from this:

To this:

So I am not sure what to do next, when should I move it to the bigger pot, how often to water it, to not kill it, is 5 days too often, and can I avoid having it grow and look like the bigger one on the first picture, since it looks it grows in all directions and doesn't look pretty.

Answer 1

I lived in South Texas until recently and had over 25 acres of cactus plants, so I've learned a bit about them!

Some cacti are "leaners". In nature they will flop over unless they find a tree, shrub, structure, etc., to lean against. The Cereus group are notorious leaners and yours might be related. As to growing new plants from sections of others, in my experience that is not only the easiest way to do it but also very common in nature. If your new plants are growing to your satisfaction, there probably won't be a need to repot them for some time. However, as you've probably learned from your big cactus, handling a pot with multiple cactus plants or multiple limbs growing in it is exponentially more difficult than handing a pot with one. So, you might want to separate them. As to watering, like almost all plants your cacti will let you know when they're thirsty by looking wilty or even shriveled. That's when you water them. Honestly, more plants are killed by overwatering than underwatering.