In 1912, the Japanese government gave the United States thousands of cherry trees to grace the Tidal Basin in our nation's capital. While the white-flowering yoshino cherry trees receive most of the attention, Japanese flowering cherries (Prunus serrulata) were also donated and planted. Always prone to disease, this species can grow in the colder winter parts of Louisiana, but don't expect the trees to live for very long. Among the cultivars of Japanese flowering cherry are Kwanzan and Mt. Fuji.
Louisiana winters are cool but mild. For a Japanese flowering cherry to bloom well, ample winter cold is needed to ensure flower buds develop and open in spring. The best parts of Louisiana for growing any cultivar of Japanese flowering cherry are the parishes located in U.S. Department of Agriculture planting hardiness zone 8, where winter low temperatures dip down to 10 to 20 degrees Fahrenheit. The colder the winter, the better. Zone 8 occurs roughly north of Interstate 10.
While the Bayou State winters are mild, the summers are long, hot and humid. Growing conditions for a Japanese flowering cherry aren't ideal, especially if the soil isn't evenly moist and cool, especially if shaded by a layer of organic mulch. Within Louisiana, perhaps the best climate for these ornamental trees is north of Interstate 20, where the elevation is higher and summers just a bit cooler. This area of Louisiana is in Sunset Climate Zone 33, which is the southernmost climate recommended for this tree in "Sunset National Garden Book."
While no specific mention of growing Japanese flowering cherry in Louisiana is found through the Ag Center of Louisiana State University Cooperative Extension, other southern states do recommend it. Nearby Mississippi State University Extension does list the cultivar Kwanzan as a worthwhile tree, and even the University of Florida Extension comments Japanese flowering cherry as a recommended spring flowering tree in the Panhandle. However, do not expect this tree to live more than 10 years in the Deep South. Heat, drought, and numerous pests and diseases afflict the Japanese flowering cherry, all leading to an early demise.
In Louisiana, plant a Japanese flowering cherry in a loose, crumbly textured fertile soil. Avoid soils that are naturally hard, compacted, soggy or dry. An enriched garden bed with lots of organic matter will improve soil texture and fertility. Ample sunlight exposure encourages the best spring flowering display. Site the tree where it receives 6 to 8 hours of sun, primarily from sunrise to early afternoon. Light shade in the afternoon, especially in summer, reduces water stress and leaf scalding. Irrigate during droughts.