The garden bed in the front of my house has a row of boxwood (winter gem, I believe) and in front of that is a row of Purple Palace coral bells with 1 astilbe on each end. I had a row of Liriope as a front border but it became invasive (I think the garden center where I bought it labeled it wrong) so I pulled it out and planted a row of Japanese Painted Lady Ferns. They looked pretty but I lost half of them over the winter. Soooo, I am looking for ideas for what to plant in a row (front row, so low in height) to finish this bed. Thought about an annual but not sure what would look nice but stay in check. I don't want anything that is going to become a groundcover. Any ideas? TIA