Ask Mr. Smarty Plants

Charleston SC is in hardiness zone 8b which is similar to here in Austin, Texas but has very different climates! So plants that grow well at the Lady Bird Johnson Wildflower Center may not grow quite so well in SC.

Mexican Feathergrass (Nassella tenuissima) Requires good drainage and can't take excessive moisture. Should not be watered heavily more than once a week. Goes dormant during drought and in winter. May rot under heavy mulch. Grows well in containers. Turns brown during the winter. Trim dead portions in the spring. SC will probably have too much winter moisture for this plant if it is grown in a garden bed. Perhaps use it in containers. May self seed prolifically in SC.

Lantana (Lantana urticoides) Lantana provides summer color. In winter, some gardeners prune back lantana to keep the plants from getting too large. The stems become thorny especially with age, so caution is necessary when cutting them back. The blue-black fruit clusters are poisonous. Used as a low to medium, flowering ground cover for dry, exposed, poor sites. Crinkly leaves give off a sharp aroma when touched and they can cause a skin rash. Mature plants tend to form large mounds that may be separated into smaller plants in the winter. Hard freezes may kill the top growth of this plant in SC but it should sprout from the base. Mulch for extra protection.

Texas Bluebonnet If planting this species in areas where it has not formerly grown, it may be helpful to inoculate the soil with a rhizobium (soil-borne bacteria which form nitrogen-rich root nodules) for lupines. Propagate by sowing seed or planting seedlings in fall.
Seed Collection: Allow the bluebonnet to reseed itself by leaving the seed pods intact on the plant until they turn from yellow to brown.
Seed Treatment: Scarification will hasten germination. Put seeds in the freezer overnight and then douse with boiling water to crack seedcoats. Soaking seeds overnight is also effective. Drain water, add rhizobium, and plant.  More information on growing bluebonnets can be found on the Aggie Horticulture website.

Autumn Sage (Salvia greggii) Autumn sage is a soft, mounding shrub normally 2-3 ft. tall, with small, minty aromatic green leaves that are evergreen in warmer climates. The flowers are borne on racemes from spring to frost and can be red, pink, purple, orange, or white. Its natural range is from south-central and west Texas south to San Luis Potosi in Mexico, mostly on rocky slopes.

A popular landscape plant in the Southwest, Autumn sage is delightful to use as a small, ornamental, flowering shrub in a perennial bed or as a low hedge. Its aromatic foliage quickens the senses and its flowers are sure to draw hummingbirds. The color of its blossoms in the wild is usually red but varies from area to area, with some regions dominated by red-blooming plants, others pink, others orange, others purple, and others white, plus many shades in between. The color range has been further enhanced by breeding, resulting in many cultivars over the years. It is disease and insect free and drought tolerant, and once established, should not be fertilized. Autumn sage must have a well-drained site and cannot take shrink-swell clay soils. In clay soils, work in organic matter and amendments to improve drainage and, if possible, plant on a slope. Though generally cold tolerant, will be deciduous in regions with extremely cold winters, though some cultivars do well even in Oklahoma and Colorado, well outside of its natural range. Avoid planting it near heavy foot traffic because the stems are very brittle.

Penstemon There are six Penstemons that are native to SC.  Why not try one or two of them?

Pensetmon australis, P. calycosus, P. canescens, P. digitalis, P. laevigatus and P. smallii.

Gaillardia pulchella (Firewheel) Indian blanket is a major wildflower of the prairies and meadows. It reseeds readily and is easy to grow; good drainage is the only requirement. Rich soils will produce large, floppy plants with few flowers. Indian blanket is very easy to grow and is commonly used in roadside & meadow plantings. This species is a short-lived perennial in warm, coastal areas. The bloom period can be prolonged by deadheading and supplemental summer watering.