Ask Mr. Smarty Plants

Your plant choices all sound good, they are all native and can all survive in the limited sunlight. They will probably not grow as fast as they would in more sun, but they should be fine. The soil amendment of your heavy clay soil is also a good idea. The Lady Bird Johnson Wildflower Center recommends only plants native not only to North America but to the area in which the plants are being grown. Native plants, being accustomed to the climate, moisture and soils in which they are growing, will need less water, fertilizer and maintenance. 

In terms of spacing, although the yaupon roots would probably not be strong enough to do any harm to your foundation, 2' still seems a little close. As the plant matures, it will expand its circumference, and it should do better given a little more distance from the building, if that is practical. Rather than plant anything in between the dwarf shrubs, you might consider planting perennial herbaceous flowering plants in front of them. This will give some color and variety to your garden. The flowering plants will mostly die back to the ground in the Winter, but you have the structure of the evergreen plants to maintain interest during that time.  For additional interest, especially in the first year (perennials often don't bloom until the second year), you could add some bright annuals, selecting for different times of bloom. We are going to go to our Recommended Species section, click on North Central Texas on the map, and then Narrow Your Search first for "herbs" (herbaceous flowering plants) under Habit, perennial for duration, and part shade (2 to 6 hours of sun daily) for Light Requirements. We will repeat the process, changing only the duration to "annual." You can follow the same procedure to make your own selections. Follow the plant link to each individual plant page to learn the colors of blooms, height the plant is expected to grow and the months they ordinarily bloom.

These plants are all commercially available, and you can go to our Native Plant Suppliers section, type your town and state into the "Enter Search Location" and you will get a list of native plant nurseries, seed companies and landscape and environment consultants in your general area.

PERENNIAL BLOOMING PLANTS FOR NORTH CENTRAL TEXAS

Aquilegia canadensis (red columbine)

Asclepias tuberosa (butterfly milkweed)

Conoclinium coelestinum (blue mistflower)

Echinacea purpurea (eastern purple coneflower)

Melampodium leucanthum (plains blackfoot)

Salvia azurea (azure blue sage)

Wedelia texana (hairy wedelia)

ANNUAL BLOOMING PLANTS FOR NORTH CENTRAL TEXAS

Amblyolepis setigera (huisache daisy)

Coreopsis tinctoria (golden tickseed)

Eryngium leavenworthii (Leavenworth's eryngo)

Gaillardia pulchella (firewheel)

Machaeranthera tanacetifolia (tanseyleaf tansyaster)

Monarda citriodora (lemon beebalm)

Phlox drummondii (annual phlox)

Rudbeckia hirta (blackeyed Susan)

Aquilegia canadensis

Asclepias tuberosa

Conoclinium coelestinum

Echinacea purpurea

Melampodium leucanthum

Salvia azurea

Wedelia texana

Amblyolepis setigera

Coreopsis tinctoria

Eryngium leavenworthii

Gaillardia pulchella

Machaeranthera tanacetifolia

Monarda citriodora

Phlox drummondii

Rudbeckia hirta