I had a perennial in a planter. Mystic Blue Spires. I dont recall it being messy but I dont recall much from 4 years ago.
I was on a Salvia thread and the discussion was about them being fragile over winter. I considered myself lucky when it came back the next year. I transplanted it to the garden but it lasted only 3 more seasons.
This is it planted in a 16 inch planter. 2010
In the garden ,last seen in 2012