Let's please put this "likes to be rootbound" myth out of its' misery!
No plant likes to be rootbound. What they like is for their roots to NOT rot, which can happen so easily in a pot with dense soils, like ground dirt, or bagged mixes of predominantly tiny particles of peat. Having very little soil around the roots makes it difficult for even the most dedicated plant-overwaterers to rot the roots of their plants. This is not ideal, just a way of coping with inappropriate "ingredients" in a pot.
A more porous, chunky soil (like cactus/palm, if one is buying bagged,) can have air in it even when it is moist. Roots need oxygen and moisture at the same time to function. When there are tiny particles of any kind in a pot, such as peat, sand, silt, clay, they filter into all of the tiny spaces in a pot, eliminating the air. "Overwatering" is the label and manifestation when roots have suffocated and/or rotted, combo of both.
There is no one thing folks can put in to make soil better, but removing tiny particles of any type will definitely help. Over time, organic bits decompose into smaller bits, so even the "best" soil, if it has organic components, will need to be replaced when this happens. The speed at which this happens depends on many variables, but on average, about 1-3 years.
When these plants are crowded, the pups have to twist and contort to find a way to get to the surface. When in the ground, the pups don't come up right next to the mama. I put Sans in the ground in spring, back to pots for winter & they grow like crazy. I gave away about 10 boxes of them this fall & kept 2 giant pots.
Contortions from growing in a pot:
The more spread-out nature of the pups without the constriction of a pot:
The shape of that pot (smaller at the opening) is not good for planting directly into, IMVHO, hard to get plant out later. But, Since they don't mind being cut and torn apart and replanted, Sans would be my choice if I wasn't going to use a cache pot liner and just plant directly into that pot.
Though I have about 60 pots with more than 1 plant, I don't partner anything with Sans. Even if I wasn't moving them around so often, they use all of the space, as the roots pic shows. Also, I think Sans would literally pick a smaller plant up and push it out of the pot, when new Sans pups form under the smaller plant and rise to the surface. That could be cool to watch, if you are expecting it & ready to give the smaller plant a new home when/if that happens. That wouldn't bother me, I love an experiment, but don't happen to have a curiosity about this to try it. I'd just prefer to put Sans in the ground for summer, have less pots to tend, while they make tons of babies/pups!
Let us know what you decide!
Btw, that new container has drainage holes right?
