Try wave petunias. It gives a nice skirt.

I used Sedum Brilliant in my pots.

Brilliant is a sedum like Autumn Joy but the flower heads are a neon pink/purple late summer I do not like the red of Autumn Joy but if you like the color of AJ it would work. They bloomed after the orientals bloomed and the foilage filled the pot around the bulbs.

Thank you both, you know, I may use petunias and sedum!

I'm curious how you are overwintering your pots - outside or in the garage? I'm trying a couple different things this winter to see what will make it up next to the house.

Also, if you are doing perennials, I've had great luck with perennial dianthus in containers - very hardy and if you shear them they will bloom again. They would be good with dwarf lilies. Also try hardy mums in your pots with lilies - the lily would give some height to the mix and you can stretch your pots out till Halloween. I've had good luck in those self-watering pots and they hold over the winter very well in the garage with just a little water from time to time.

Here are the plants I've had good luck with remaining alive in pots over the winter
Hosta
perennial dianthus
Dusty Miller
Those spiky things they always put in summer planters
variegated vinca
Hardy Mums
Ice pansies - they are still blooming and its 20 outside and they had many snows on top of them.
Pachysandra - yup - looks good with the right things and is indestructible

Re-seed on their own in the same pots: nicotiana, impatiens, bedding begonias, plain purple petunias,

I'm getting lazier and lazier as I figure out ways not to have to buy a truckload of new potting soil every year and re-plant all my deck pots. I usually scoop out the top 3-4" and replace it and use Osmocote and a couple handfuls of compost.

I have not had good luck holding calladiums and acidanthera in the garage here - too cold but I had to try.

I had let the soil dry out pretty much, then covered them with black plastic. I moved them closer together and used bags of leaves all around them. All of the barrels have lillies coming back this year. Some more than others. It seems a lot of bulblets are growing, not so many big plants yet. But I did dig a little to check and it looks like the bigger bulbs are going to sprout, they're just slower I guess.

I'm experimenting with perennials. I have a shasta daisy, a columbine, a hechura and a lobelia so far. I have a sedum to transplant in the last one. Planted some annual convolvus seeds in there too.

Had experimented with wintersowing this year too. I just may uncover them next Mar/Apr to wintersow some peas, then use clear plastic til the peas sprout. I have my wintersown peas in pots now and they're doing great. I hope it will add nitrogen to the soil for the lillies. What do you think?