I think it's because they're forced in heated polytunnels and imported from Holland, so they simply don't last long, especially if planted out. Sorry - but I'd treat it as a temporary houseplant. *Definitely* don't eat it! :-O lol.

I threw out some miniature white roses a few years back. They are still there and flowering now, more cream in colour and closer to 30-40cm now.

They should grow outside - what often kills them is having been indoors and then put outside if the overnight temperatures aren't very high - the shock of change polishes them off, because they won't be in the best of health from being indoors.

Try planting it, though if your overnight temperatures are low, harden it off first a bit. Keep well watered once planted - as for size, who knows - miniature roses vary between 1 to 7 feet in the ground, depending on variety.

I put some into my borders and they keep flowering ok for me here. As bamboo says it is the shock of change in temperature that kills them off.

7ft mini....not for the front of the rockery then

Er, no!