Southern Louisiana experiences a semitropical climate with sunny days and high humidity levels. The southern part of Louisiana falls within USDA hardiness zones 8 and 9. If you live in this region, select flowers according to plant hardiness, flower color, bloom time and mature size. Numerous flowering plants thrive in Southern Louisiana gardens.
Louisiana phlox (Phlox divaricata), also called the wild blue phlox, naturally occurs in woodlands across Southern Louisiana. This phlox family member (Polemoniaceae) blooms from March through May. Fragrant clusters of pale blue flowers grow at the base of stems, while pink or purple blossoms bloom near the top. Mature plants reach from 8 to 18 inches long. This plant likes moist, acidic soils in partly to fully shady locations. Gardeners often use this plant in perennial flowerbeds and butterfly gardens.
The zigzag iris (Iris brevicaulis) grows from bulbs and reaches up to 2 feet in height. The zigzagged stems bear light purple, white or blue flowers with dark veins. This Iridaceae perennial family member typically blooms in early to mid-spring and prefers moist, rich soils that receive partial shade. Southern Louisiana gardeners often plant zigzag irises in shady woodland gardens, swamp margins and bottomlands.
Closed Bottle Gentian
Closed-bottle gentian flowers (Gentiana andrewsii) look like buds even when in full bloom. These Gentianaceae family members reach up to 2 feet in height and likes moist to wet, humusy soil in shady positions. This perennial gentian variety features thin, purple leaves and purple or blue flower clusters that bloom from August through the first frost. The closed-bottle gentian grows well in wildflower gardens and meadows.
Flaxleaf Whitetop Aster
The flaxleaf whitetop aster (Ionactis linariifolius), sometimes called the stiff aster, belongs to the Asteraceae plant family and adds late summer color to Southern Louisiana gardens. The flowers consist of pink or lavender petals surrounding yellow to bronze central disks. This perennial plant tolerates various lighting conditions, but prefers sandy soils. The flaxleaf whitetop aster performs well in rock gardens and dry clearings.
Scarlet rosemallows (Hibiscus coccineus), also known as wild red mallows, feature dark red flowers that reach over 6 inches in diameter. This Malvaceae family member blooms from July through September. The scarlet rosemallow prefers wet soils that receive full sun. Mature flowers reach up to 6 feet in height. Southern Louisiana gardeners often plant the scarlet rosemallow in swamp margins and around ponds.
The purple passionflower (Passiflora incarnate), sometimes called the apricot vine, naturally occurs along Southern Louisiana roads and rivers. This perennial vine reaches up to 25 feet in length and prefers rich, sandy or loamy soils in sunny locations. This Passifloraceae family member features pale purple, pink or blue flowers with showy stamens and pistils. The flowers bloom from April through September, giving way to edible, yellow to orange berries called maypops. Southern Louisiana gardeners often use the purple passionflower along stream banks and as groundcovers. These vines can also be trained to climb arbors, walls and fences.