Most of Louisiana is in USDA Hardiness Zone 8 with just a small section in the south in Zone 9. Evergreens in Louisiana need to be able take the warm weather and are different than the evergreens found further north. Evergreen trees and shrubs are available for all levels of moisture from dry to boggy.
Atlas cedar (Cedrus atlantica) grows from 40 to 120 feet tall with a crown spread of 20 to 100 feet. The tree features a silver-gray trunk and stiff blue-green needles. The evergreen produces 3-inch long, egg-shaped cones that start out green and become brown when mature. Plant atlas cedar in full sun or partial shade and a soil that is moist to dry. The tree is hardy in all of Louisiana.
American olive (Osmanthus americanus) is also known as devilwood and wild olive. The plant is a small tree or large shrub growing from 10 to 50 feet tall with a spread of 8 to 15 feet. The tree produces elliptic-shaped leaves that measure 2 to 6 inches long and small, white, fragrant, flowers growing in clusters, blooming in March and April. Plant American olive in full sun or partial shade and a soil that is moist to dry.
Japanese plum (Eriobotrya japonica) is also known as loquat. The tree grows to about 20 feet tall producing leaves that are dark green on top, light green on the bottom and grow up to 10 inches long. The fragrant, white flowers grow in clusters in late fall and are followed by small, edible yellow fruits that appear in the spring. Plant Japanese plum in full sun and a moist, well-drained soil. The tree is hardy in all of Louisiana.
Red bay (Persea borbonia) grows up to 65 feet tall with a trunk up to 3 feet in diameter. The tree produces oblong or lance-shaped leaves that grow from 4 to 6 inches long and a small, blue or black fruit. Plant red bay in light shade and a soil that is moist to dry. The tree is hardy in all of Louisiana.
Swamp bay (Magnolia virginiana) is also known as sweet bay and silver bay. The tree grows from 40 to 75 feet tall with leaves that are green on top and silver on the bottom and small fruit that becomes red when it matures. Plant swamp bay in partial shade and a wet and boggy soil. The tree is hardy in all of Louisiana.