Different opinions on that.I plant those type in ground.I leave all four together,that way I can get as impressive shrub as possible.In my area I don't have to cut back.I do have to thin out the middle.Others seperate them.Either works.they will need to be sprayed.

I do the same just plant right from the pot and they do great

I also replant them all as one bush...they grow to be very impressive very quickly. Some rose enthusiasts denouce these as 'throwaway roses' since most of the time they are unnamed varieties...but in reality I love the grocery store mini rose for the very reason that you can get 4 plants in one and I have had very good luck with replanting these and having them knock my socks off and outperform other minis.

I actually just bought one from Whole Foods today on an impulse, the bush is huge and it's 4 plants with a very large (for a mini) pure soft pink bloom, very beautiful. It'll be great in my patio garden.

Good luck!