Yes,you could add other evergreen rock,hosta,dogwood,boxwood,juniper,azalea ...too.

{{gwi:18654}}

It would help to know your USDA zone, also roughly where you live so we have some idea of the high temperatures you get. You can look up your zone here; just put in your zip code:
http://www.garden.org/zipzone/index.php

The plants in ideasshare's photo aren't to scale, so you shouldn't put too much faith in that depiction.

I agree it would help to know your zone. Also, my strong suggestion is ammend your soil with compost or manure. I find topsoil doesn't do anything to help plants thrive.
Some ideas: Abelia are nice and evergreen with PINK flowers. Some varieties are prettier than others and some are fragrant, too. I'd plant 3 of them along the brick wall in a not perfect row - sort of curved. A few low growing knock out roses scattered in front of the abelia. (Depending on what type of maintence you want you can do old garden roses too) Then possibly a juniper type ground cover. I'd space your agapantha out and add more so they make the curve. You can also add some annual color at the edge. This space can be beauitful but please consider improving your soil. If it gets enough shade and the soil is good hydrangea would do well there but they are bare in the winter so you might want to inter plant with something evergreen. Do gardenia grow well there? In my previous home I had a row of gardenia and at the end a HUGE 20 year old hydrangea and they were great together.
If you're in the cooler area hosta would also look nice, especially as an edger.
Sunny

Thanks. I don't know why my zone disappeared.

I will also add some manure.

I was considering dwarf oleander in the back. I am not sure if they make a pink variety of that or not. Anyone know?

Down in front, I added margerite sweet potato vine to spread out and reduce the need for so much mulch.

Thanks for the responses so far.

I'm in Texas zone 8. Aren't dwarf oleanders a little cold tender for your area? Looks like a lot of direct light for daylilies, perhaps too much for a sweet potato vine as well. Don't they require frequent watering? Some Harbour Dwarf nandina would give you some nice color in that area. There is also a pink blooming dwarf ruellia, and some lantana blooms pink (sort of, anyway.)