I was, admittedly, overzealous and I posted this question on several different forums. Sorry all.

Here's what I did: I purchased a large Gold Flame spirea, moved one hydrangea out and left the other one in the plater, relocated to the shade of my azalea, placed 3 or 4 large clumps of white calla lilies near the back (the planter was full of callas), planted 5 dwarf agapanthus in the front for year-round green. I also flanked the sides and back of the agapanthus with pink and orange calla lilies, which die back in winter. 30 paperwhites bulbs near the gardenia, grape hyacinth along the edge, hosta in a shady area under/behind the gardeina (you can see it when you look outside from the front door).

After finishing this rearrangement/redesign, most of the stuff in the planter looks bad. The gardenia and azalea haven't shown any signs of being upset, the hydrangea is wilty more frequently but hasn't dropped leaves. All the callas lost their leaves (they always do when I transplant them) but the white ones have sent up more and the colored will probably by back in the spring. The bulbs are okay, leave a bit dry but not brown.