I bought a very nice looking rosemary plant at Lowe's. I went to transplant into a slightly larger clay pot. Much to my surprise, there were 4 plants all the the one tripped pot. The "Ball" removed from the previous pot was nothing but roots. No soil seen, no soil fell loose, just a solid mass of roots the size and shape of the container,

So they are transplanted, with about an inch of soil surrounding the root ball.

I would think I need a larger pot, BUT

Should I leave the 4 plants combined into one pot, or try to separate one out and save it?

Suggestions welcome! Please!